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In the Zeitschrift für Elektrochemie (vol. xii., p. 513) the figures of Marignac in the analysis of silver chlorate; of Prof. W. Kistiakowsky points out the existence of a Dixon and Edgar, by the direct determination of the ratio relationship between the surface-tension values of different H:Cl; and of Richards and Wells, the ratio Ag : AgCl. liquids which is analogous to the well-known Trouton's In this way the results of the chemical and physicorule. If k denote the capillary constant of a liquid at its chemical methods are brought into agreement, leading to boiling point, m the molecular weight, and Tthe boiling the conclusion that the atomic weight of silver should be point on the absolute scale, then mk/T is constant and
lowered from 107.93 to 107.89. equal to 0-0116 for about forty non-associated liquids which have been examined. In the case of associated liquids, such as the alcohols and fatty acids, the value of mk/T
OUR ASTRONOMICAL COLUMN. is much smaller, and account of the considerable
ASTRONOMICAL OCCURRENCES IN OCTOBER:change in the value of the factor it appears to be eminently Oct. 2.
Pallas (mag. 8:0) in opposition to the Sun. suited for ascertaining the existence of association in the
3. 9h. 19m. Minimum of Algol (B Persei). liquid state of aggregation.
15h. 35m. 10. 16h. 52m. Moon occults u Ceti
(mag. 4:4). Tue report of the principal chemist of the Government 6. 12h. 30m. to 15h. 28m. Transit of Jupiter's Sat. III. Laboratory for the year ending March 31 furnishes some
(Ganymede). interesting reading. The total number of samples examined
9. 16h. om. Jupiter in conjunction with Moon (Jupiter
2° 12' N). at the laboratory at Clement's Inn Passage during the
15. Venus. Illuminated portion of disc =0'333; of year was 106,779, the greater part being in connection
Mars =0.976. with the revenue departments. In the Customs the in- 18-22. Epoch of October meteoric shower (Radiant 92' +15 1. crease in the number of samples examined, as compared
nh. im. Minimum of Algol (B Persei).
25. with last year, was 2389, the Excise showing an increase
6h. 49m. to 6h. 56m. Moon occulis i Capricorni of more than 18,000.
(mag. 4 3). Special attention was given to
19h. om. Venus at greatest brilliancy. establishing a systematic check on the “obscuration
26. 7h. som. Minimum of Algol (B Persei). enumerated spirits, that is, the change in the apparent
Saturn. Major axis of outer ring =42" 62 ; minor strength of spirits, as determined by the hydrometer,
axis = 4"73. caused by the presence of solid matters in solution. It
29. 13h. om. Jupiter stationary. is noteworthy that, in the case of tea, the evidence of THE Total Solar Eclipse of JANUARY, 1907.-In a letter deliberate adulteration was extremely rare.
to the Observatory (No. 374), Mr. W. T. Lynn discusses portion of the tea entering the country was declared
the accessibility and suitability of Andishan as a place
wherefrom to observe the total eclipse of the sun which to be unsound and unfit for human consumption. Such
will take place in January next year. This town is condemned tea does not pay duty, and, after being situated to the north-east of Samarkand, in the Khanate denatured by the addition of lime and asalætida, is allowed of Khokand, its approximate position being long. = to be used in the manufacture of caffeine. Little improve- 72° 17' E., lat. = 40° 50' N. It is on the Russian Centrai ment is shown in the freedom from adulteration of the
Asiatic Railway, about 170 miles south-east of Tashkent.
As a beer supplied by publicans ; 11.1 per cent. of the samples Orenburg, the journey from Europe should prove a
new line of railway runs to the latter place from taken were found to be diluted. There is good reason,
paratively straightforward one. Indishan lies in the fertile moreover, to believe that a notable amount of butter valley of Ferghana, at the junction of the river Kara adulteration takes place in this country. A considerable Darya (a tributary of the Syr Darya) and a smaller stream', increase is shown in the quantity of duty-free spirit used
so that there should be little difficulty in finding a suitable in colleges for purposes of research.
observing site for the eclipse parties. The eclipse will
take place on January 14, 1907 (civil time), and the shadow Since the atomic weight of silver is the basis upon which
track will be very narrow, thus limiting the choice of most of the atomic weights of other elements are founded,
stations; the duration of totality will be about two minutes.
By an obvious slip, the date is given as January 4 and even a small change in the accepted value is not without
the duration of totality as two seconds in Mr. Lynn's importance. The Comples rendus for September 10 con- letter, as published in the Observatory. tains a note on this subject by P. A. Guye and G. Ter
OBSERVATIONS OF PHEBE IN MAY AND JUNE, 100.Gazarian. Owing to the great improvements in recent Circular 118 of the Harvard College Observatory gives the years in the methods of dealing with gases, physico- positions of Phæbe, the ninth satellite of Saturn, as deteta chemical methods of determining atomic weights, originally
mined from six photographs obtained between May 18 ard only used as a rough guide for the purely chemical methods, June 28, with the 24-inch Bruce telescope, at Arequipa. have reached an accuracy at least equalling the latter. If
The places thus obtained are compared with those giorn
by the ephemeris published in the Nautical Almanac for the atomic weights of carbon, hydrogen, nitrogen, and 1906, the differences (O-C) in R.A. and declination bens chlorine related directly to oxygen by physicochemical given. methods be taken as a basis, the value 107.89 is obtained THE COLOURS OF SUN-SPOTS.--In the September numurs for silver instead of 107.93, obtained by Stas by the use of the Bulletin de la Société astronomique de France of chlorates, bromates, and iodates. The authors give a
M. Th. Hansen, of Praestö, Denmark, states that train summary of the work done by various workers on the many years' observations of sun-spots he is convinced that latter compounds, and note a possible cause of error in
sun-spots exhibit colours proper to themselves, and no
merely the results of instrumental chromatinn. the presence of potassium chloride in the potassium chlorate
observes that the spot nuclei are rarely, if ever, a dead used. They show that these two compounds, on account black, but generally are of a decided violet colour I he of the fact that the chloride forms a solid solution of preceding part of the spot is most often of a yellow color, nearly constant composition, are very difficult to separate. whilst red is generally predominant in the
“ following They find that potassium chlorate, purified as far as
parts, although green is also seen there. On August 11,
1903. a small but dazzling white facula appeared in the possible by re-crystallisation, contains 2.7 parts of chloride
centre of a black spot whilst M. Hansen was drawing the per 10,000. Applying this correction to Stas's figures, an
Two plates showing the colours observed in the atomic weight of 107.89 is obtained, nearly identical with large spot of November, 1903, accompany the 1911.3117
cation, and M. Hansen suggests that the colours of spots initiated a discussion on the problems connected with the may eventually be differentiated by spectroscopic obsery- Palæozoic glaciation of Australia, India, and South Africa. ations.
He pointed out that in Australia we have evidence of three COLOURS AND MAGNITUDES OF DOUBLE STARS.-It is a
horizons at which glacial beds occur, the Cambrian, the
Carboniferous, and the Pleistocene. The Cambrian glacial generally accepted statement that when the magnitudes of
beds near Adelaide range 400 miles north and south, and the components of a binary-star system differ considerably their colours are also very different; similarly a slight
are interbedded with marine sediments containing a rich difference in magnitude is usually accompanied by a
Cambrian fauna. Evidence of Pleistocene glaciers has only
been found on the mainland near the summit of Mt. similarity of colour.
Kosciusko, the highest mountain of Australia. The Whilst preparing his recently published and valuable
Carboniferous glaciation is the most important, and prememoir on the double stars of Struve's “ Mensuræ Micro
sents points of the greatest interest. While in the State metricæ Mr. Lewis has gathered striking evidence that
of Victoria there exists undoubted evidence of land ice these statements are true, and in No. 373 of the Observ
riding over an irregular land surface, in New South Wales, atory he gives a table of physical pairs, from which it is
West Australia, and in India the glacial beds include some seen that a gradual increase in the differences of magnitude
that were laid down below sea-level. Beds presumably of is accompanied by constantly increasing differences of
this age are also found in South Africa, South America, colour. A discussion of fifty double stars situated in the
and perhaps on the eastern flanks of the Urals. Prof. southern hemisphere corroborates this evidence.
Gregory pointed out the inherent probability of these beds ROTATION PERIOD OF JUPITER'S EQUATORIAL REGION.--In having formed part of a once continuous sheet of glacial No. 4117 of the Astronomische Nachrichten Mr. Denning deposits. No proof is forthcoming that they publishes the rotation periods, derived from a number of synchronous, and in Africa and Australia the glacial spots situated on the equatorial side of the southern equa- evidence disappears to the north, ending about the southern torial belt of Jupiter, as determined by him at Bristol in tropic, and begins again in the northern hemisphere in the years 1898 to 1905-6 inclusive. From the tabulated latitude 17° 20 N., increasing in strength northwards to statement given it is seen that the rate during 1905-6 was Cashmere. several seconds slower than in previous years. During After a critical survey of the three theories which have 1880-3 the rotation period was from eighteen to twenty- been advanced to explain this problem, viz. (1) the shiftseven seconds shorter than during 1905-6.
ing of the earth's axis (Oldham and Penck); (2) a universal refrigeration of the world due to a change in the composi
tion of the earth's atmosphere (Arrhenius); and (3) local GEOLOGY AT THE BRITISH ASSOCIATION. concentration of snowfall in consequence of a different
distribution IT is only natural that the salient geological features of
land and water, Prof. Gregory concludes the district in which the association meets should in that the last is alone adequate to explain the facts. some degree influence the character of the papers pre
In the discussion which followed, Prof. Edgeworth sented to Section C. Yorkshire, being rich in glacial and
David and Mr. T. H. Holland argued in favour of post-glacial problems, it is not surprising that special | Arrhenius's theory, as the cause must have been worldattention was directed to the more recent episodes in the wide, and the phenomena could not be accounted for by carth's history. The presidential address dealt with local changes in topography. Mr. R. D. Oldham favoured British drifts and the inter-glacial problem, and, after a
Prof. Chamberlain's adaptation of Arrhenius's carbonic review of all the evidence bearing on the question, Mr.
acid theory, and pointed out the analogies between the Lamplugh pronounces that no proof of mild inter-Glacial great revolutionary epochs of the earth's history, all of pochs, or even of one such epoch, has been discovered
which are associated with glacial phenomena. during the examination of glaciated districts in England, The stratigraphical papers certainly showed bias Ireland, and the Isle of Man. The “ Middle Glacial towards the Carboniferous period. No less than five papers sands and gravels of our islands afford no proof of mild were read, dealing mainly with the faunal succession and inter-glacial conditions or of submergence. In most cases,
zoning of beds of this age. The recent work of Dr. if not in all, they represent the fluvio-glacial material Wheelton Hind, Dr. Vaughan, Prof. Garwood and others, derived from ice sheets. Most of the fossiliferous beds as detailed in their papers, shows great strides towards regarded as inter-glacial contain a fauna and fora com- the completion of what, at one time, seemed a hopeless patible with cold conditions of climate, and, in the excep- problem. cional cases where a warmer climate is indicated, the A discussion on the origin of the Trias was opened by relation of the deposits to the Boulder-clays is open to Prof. Bonney and Mr. J. Lomas. Prof. Bonney considers question.
the Bunter to be chiefly of fluviatile origin, the rivers Prof. Kendall followed the president's address with a carrying the materials having their origins in Scotland, full and comprehensive account of the general geological the extreme north of Ireland, and another flowing from structure of the country round York, and dwelt specially the south-west. The Keuper he regards as indicating the on the glaciation of the Vale of York and the Cleveland setting in of inland-sea conditions, and the Red Marl as Hills. During the meeting the members were enabled to having been deposited in a great salt lake. The physical visit the York moraine and study the glacier lakes and and climatal conditions of the Trias were probably to some werflows in the eastern part of the county under the extent comparable with those now existing in certain of guidance of Prof. Kendall.
central parts of Asia, such Persia or Other local glacial papers dealt with the Kirmington Turkestan. Drift deposits, recent exposures of glacial drift at Don- Mr. Lomas compared the Triassic deposits with those caster and Tickhill, post-glacial deposits at Hornsea, and now forming in desert regions. He pointed out that the the plain of marine denudation beneath the drift of Holder- dominant feature of deserts is concentration. The wind
acting on loose material concentrates particles of equal Contributions dealing with drift problems farther size in one place, an arid climate tends to concentrate the afield were presented by Mr. F. W. Harmer, who con- salts brought down by rivers in solution in shallow pools tinued his work on the glacial deposits of the east of held up by the irregular disposition of sand dunes, and England, and in another paper he applied the brilliant animal and plant life is concentrated in those regions where results obtained by Prof. Kendall in the Cleveland district water is more or less permanent. Taking the various to support his theory regarding “ Lake Oxford and the divisions of the Trias, he showed that in the Bunter the origin of the Goring Gap.
pebble beds of the Midlands may be compared with those The Rev. W. Lower Carter applied the same results to of Lancashire and Cheshire, the only difference being that explain a drv valley which had been a glacier-lake overflow the former may have been subject to the sisting action of at Cwm-Coed-y-cerig, in South Wales, and gave a detailed wind, which has removed the smaller sand particles, while arcount of the local glaciers which formerly existed in the the latter has, in part, escaped this action, and has been valleys of the Usk and Wye.
augmented by material from the south. The Upper Bunter Mr. R. D. Oldham brought forward a criterion of he cited as a striking example of concentration of particles glacial erosion of lake basins, and Prof. J. W. Gregory of even size. The Keuper shows evidence of similar sift
ing, and is characterised by an increasing frequency of the wide distribution of many fresh-water organisms over Marl bands. These he regards as evidences of shallow the land surfaces of the world. He held that the difficullakes, and compares them with similar pools now found ties in the way of the migration of these animals were in the desert regions of South Africa. The muds forming so great that their wide distribution could not be attributed the floors of these pools, both in the recent and older solely to such migration. He suggested that in all probexamples, contain Estheria, and afford impressions of foot- / ability the sea is becoming more salt, and that this change prints, raindrops, and desiccation cracks. The Keuper may have been concerned in the production and separation Marls he compares with the Loess of eastern Europe, and of marine and fresh-water faunas. Whatever the actual the beds of salt, gypsum, and other salts he regards as the cause of separation, as the general fresh-water fauna ot result of evaporation in lakes.
the globe possessed certain archaic characters it would be Mr. Holland referred to certain phenomena in the convenient to name this the primary fresh-water fauna. Rajputana desert that supported Mr. Lomas's views with To this primary fauna there are added in many places, regard to the processes of concentration in arid regions, e.g. in the Caspian Sea, animals which have, from thuis and gave evidence of the sifting action of wind in India. structure and affinities, been obviously derived from the sea, Similar bands of silt and mud are found filling in hollows and have an origin independent of that of the fresh-water in the Archæan rocks. He was not prepared to admit fauna of the region in which they occur. To these animals that the features of the British Trias were due only to Mr. Moore applied the name halolimnic. There are in wind action, but in the main they were due to conditions Tanganyika a number of animals peculiar to that lake, ard prevailing in desert regions. Prof. Cole pointed out that, regarded by Mr. Moore as halolimnic. The mollusca of the in dealing with the ritish Trias, we must not forget the lake are represented by certain ordinary fresh-water forms, great sea eastwards and the likelihood of the establish- | but, in addition, there are several not closely related to any ment of a monsoon system on its margin. This might set recognised fresh-water type, nor does their anatomy suggest up an intense rainy season for, say, three months in the that they have been evolved from any African fresh-water year, followed by a dry season. Sheets of pebbles without form; there are four Polyzoa, only one of which is well-defined water channels are compatible with general phylactolæmatous, and it may be inferred that the other evidence of desiccation. Mr. R. D. Oldham showed that three are derived from marine forms, while the occurrence the only agency forming pure sands comparable with the of a medusa is also suggestive in this connection. There Trias is wind. Mr. Clement Reid compared the peculiar are three possible explanations of these faunistic peculiaristiff-stemmed flora of the desert with those found in the ties :-(1) that they are due to direct modifications of the Trias.
general African fresh-water fauna; (2) that they are conThe papers dealing with palæontology were more than stituted by the presence in the lake of the remains of an usually interesting. Mr. C. G. Danford exhibited and de- extinct fresh-water fauna; (3) that they are due to the scribed a fine series of ammonites from Speeton. Mr. presence of halolimnic elements. Mr. Moore regarded the A. C. Seward dealt with the Jurassic flora of Yorkshire, last the correct explanation, and referred to the and Dr. H. Woodward, in describing a wonderful collec- similarity of the shells of certain Tanganyika gastropods tion of arthropods from the Coal-measures at Sparth to those common in Jurassic seas. The evidence points to Bottoms, showed what an enthusiastic band of collectors Tanganyika having been isolated a long time from the can do, when work is taken in hand in the spirit which characterises the Rochdale geologists.
Mr. W. A. Cunnington gave a brief account of the third The report on the fauna and Hora of the Trias included Tanganyika expedition, from which he had recently rean important paper by Dr. A. Smith Woodward on turned. 115 fishes are now recorded from the lake, 102 0 Rhynchosaurus articeps, and Mr. H. C. Beasley and Mr. which occur nowhere else. Twelve species of prawns (of Lomas described the great finds of Triassic foot-prints which only one has been found elsewhere) all which have recently been discovered Storetor, in specialised in the direction of reduction of gills, and the Cheshire, and Hollington, in Staffordshire.
four species of crabs are all endemic. These facts are In petrology and mineralogy great interest was shown probably to be explained by the long isolation of the lake. in the announcement by Prof. Edgeworth David that It is curious that no Cladocera were met with in Tangandiamonds had been found embedded in the matrix near yika, though they are abundant in Victoria Nyanza and Inverell, New South Wales.
Lake Nyassa. Mr. T. H. Holland demonstrated the peculiar properties Prof. J. W. Gregory considered that there are of a variety of sodalite from Rajputana. When freshly evidences of marine rocks in the plateau of equatorial broken it has a bright carmine colour, which changes to Africa, though it is evident that the plateau is of great dull grey on being exposed to light. The carmine colour antiquity. The idea of the occurrence of the sea in the returns when the specimen is kept in the dark. Prof. Tanganyika valley should be abandoned. He suggested H. S. Reynolds dealt with the igneous rocks in the district that the halolimnic fauna is rather to be explained as south-west of Dolgelly, and described the occurrence of a a part of an ancient lake fauna at one time widely dispicrite from the eastern Mendips.
tributed over Africa, but now surviving only in Tanganyika In general geology Mr. J. Parkinson gave an interest- Prof. Pelseneer pointed out that the external resemblances ing account of the post-Cretaceous geology of Southern of shells are often illusory, and the results to which thes Nigeria, Prof. Cole outlined a scheme of geology suited lead quite uncertain, therefore only the study and comto agricultural scholars, and Prof. J. Milne discussed parison of the internal organisation of the molluscs can certain earthquake relationships.
throw light on the question at issue. Messrs. Moore and While the time of the section was fully taken up by Digby have suggested that some of the Tanganyika the consideration of the above subjects, no less than thirty- | molluscs have affinities to certain marine forms, Chytra seven papers dealing with strictly geological matters were being related to Hipponyx and Capulus, Spekia to read in other sections.
Lamellaria, and Edgaria (=Nassopsis) to the Architänin
glossa ; but Prof. Pelseneer held that there are really no ZOOLOGY AT THE BRITISH ASSOCIATION. affinities in the usual sense of the word, between these
forms, but only distant resemblances, such as are common THE large attendance at many of the meetings of Section D was sufficient evidence of the general ! limnic" forms belong.
to all the Tænioglossa, to which group these “ halo
Nor do they present archaic interest of the programme, which included discussions upon
characters to a greater extent than other fresh-water genera the Tanganyika problem, the nature of fertilisation, spicule not“ halolimnic,”' such as Ampullaria and Paludina. Prof. formation in sponges, the bearing of scientific marine in- Pelseneer concluded that all the “halolimnic" gastrop de vestigations on practical fishery problems, and a number of belong to the family Melaniidæ or to closely related topes. papers on special subjects, only a few of which can be as is shown by their raduiæ, otocysts, &c., and by seca! noticed here.
details of their biology--their fresh-water habitat and The Tanganyika Problem.
viviparity. The study of two genera (Giraudia and The discussion on the Tanganyika problem was opened Lavigeria) the organisation of which has only just herung by Mr. J. E. S. Moore, who dealt, first, with the investigated supports this conclusion. Both have in their characters of fresh-water faunas in general, pointing out otocysts multiple otoliths, one otolith being much larges
than the others in two species of Giraudia. Lavigeria, the
Spicule Formation in Sponges. only genus of which a female has been examined, is vivi
Prof. Minchin discussed a number of facts bearing on parous, and its radula most closely resembles that of the Melaniid genus Chiara, while the radula of Giraudia is
spicule formation in calcareous sponges, and concluded that clearly similar to that of the Melaniid genus Ancylotus.
the form of primary spicules is in no way dependent upon Dr. G. A. Boulenger, in reviewing the evidence afforded
the physical properties of the material (calcite), but is by a study of the fishes, said that the Cichlid fishes, which
regulated solely by biological conditions. When, however, form so large a proportion of the fishes of Tanganyika,
primary spicules are joined together to form spicular are examples of an extraordinary modification of one type
systems, the physical properties of the material may exert which has entered fresh water all over Africa, and that
an influence upon the form of the spicule as a whole by this lake seems to have served as a nursery for genera and
determining the angles at which the rays join together. species of this family. The Cichlids of Victoria Nyanza
Prof. Dendy dealt more particularly with the evolution of seem to have arisen, like those of Tanganyika, from a
the various forms of siliceous spicules in the Tetraxonid small number of generalised types. The fishes of Tangan
sponges, showing that they are all derivable from a primivika indicate a long isolation of the lake, perhaps extending
tive tetraxon form. He showed that these spicules originback to Miocene times.
ated singly in mother-cells, and endeavoured to explain their great diversity of form as the result of the action of
variation, heredity, and natural selection. Mr. W. WoodThe Nature of Fertilisation.
land contended that the forms spicules are not inherited, The discussion (conjointly with Section K) on the nature
for such an inheritance of forms of spicules adapted to the of fertilisation was initiated by Dr. V. H. Blackman, who
architecture of the organism implies that wandering cells gave a brief account of the recent work on which the (scleroblasts) are severally able to produce a part of the present views of fertilisation are based, dealing specially adult organism, an organ, in fact, related in form to the with the role of the chromosomes, and taking as a starting other parts. The collection of scleroblasts disposed about point the theory put forward by Montgomery (1901), that the spicule forming the protoplasmic mould in which the in synapsis the maternal and paternal chromosomes unite spicule is deposited is the organ assumed to be inherited. in pairs and are later separated by the reduction division, Such a theory seems to be contradicted by the facts of which thus divides the somatic chromosomes into two experimental embryology, which shows that a blastomere groups. Fertilisation appears to be incapable of exact de- can only give rise to an integral part of the adult organism finition, for apogamy and parthenogenesis link it on to in virtue of its localised connection with other blastomeres. vegetative reproduction, and, indeed, nuclear fusions and Mr. Woodland concluded, therefore, that the form of the r.ductions occur in plants apart from reproduction, e.g. in i deposited spicule determines the disposition of the sclerograft hybrids of Mespilus and Cratægus there is evidence blasts, and not vice versâ (as held by the advocates of the that the fusing of vegetative cells has led to the mixing inheritance of spicule form), and that spicular phenomena of characters.
may be fully explained by reference to known physical facts. Prof. Calkins described his experiments proving that it He suggested that many spicules are probably closely allied was possible to carry cultures of Paramecium through a in their mode of origin to the curious structures (colloidocertain number of periods of depression, and to renew their morphs) formed by mineral substances deposited in colloidal vitality by means other than nuclear fusion (conjugation), media. he having been able to do this by treatment with beef
Fishery Problems and Marine Investigations. extract and with extract of pancreas and brain. Prof. M. Hartog cited what he considered to be comparable cases
Dr. E. J. Allen opened a discussion on the relations of of the orange, Funkia, &c., where cells of the nucellar
scientific marine investigations to practical fishery problems. tissue grow into the embryo-sac cavity, and, under the
He pointed out that the great growth of the fishing instimulus of the exceptional nutrition, grow into embryos dustry during the last thirty years has been accomplished which behave exactly like the normal embryos produced by by, practical fishermen, and, in some directions at least, the fertilised oosphere in the same favoured feeding place.
science could even now help little, e.g. in the case of driftMr. L. Doncaster gave a brief account of the maturation
net fisheries any attempt to increase the supply would of parthenogenetic eggs, pointing out that many eggs which probably be futile. In the case of trawl fisheries a diminuproduce, not only one, but two polar bodies, may develop
tion in the source of supply has taken place, but there is parthenogenetically. The fate of the polar nuclei varies hope of increasing the actual supply of fish in the grounds considerably; in some cases they are cast out and lost, in by (1) regulation and restriction of fishing ; (2) re-stocking others they remain in the egg, and (as in Artemia) one
exhausted grounds by hatching or by transplantation; and may conjugate with the egg nucleus, taking the place of
(3) destruction of the enemies of food fishes. Before such the spermatozoon.
measures can be carried out with much hope of success, a Dr. Rosenberg (Stockholm) described his experiments on
complete and exact knowledge is necessary of the habits the production of hybrids of Drosera rotundifolia and
and life-histories of the fishes, and of the conditions under D. longifolia, the cells of the former having ten and of
which they live. the latter twenty chromosomes. In certain of the daughter
Dr. W. Garstang discussed the question of the diminution nuclei, ten, eleven, or twelve chromosomes move to one of the stock of plaice in the North Sea, and the methods
The diminution is pole during division, the same number to the other pole, suggested for increasing the supply. and between these lie a number of separate chromosomes,
supposed to be caused by the excessive fishing of young fish. which are later taken into one or other of the division in the southern part of the North Sea (Flemish Bight) nuclei. In Hieracium, one polar nucleus returns to the most of the fish caught are less than 30 cm. in length, embryo-suc cell and fuses with the egg-cell, producing a while on the Dogger Bank most are more than 30 cm. call with unreduced number of chromosomes. Dr. Ostenfeld long. From January to June the small plaice are found afterwards stated that Hieracium was able to produce chiefly inshore and out to the u-fathom line; from June fruits without ordinary fertilisation having taken place. to December they travel out to the 20-fathom line. This
Prof. Hickson considered that the evidence that the gives a rough idea of the migration of the young plaice chromosomes the sole bearers of the hereditary outward into deeper water during the summer and autumn characters had been much weakened during recent years
months, and is confirmed by the results of marking experiby the results of such experiments as those on enucleated ments. The migration of fish to the Dogger Bank is, thereeggs fertilised by the sperms of another species, which gave fore, not a direct and simple one, but takes place in at rise to larvæ showing sometimes paternal and sometimes least two stages. Much more information is still required maternal and mixed characters.
concerning the normal distribution of fishes of various sizes, Mr. H. Wager pointed out that in many of the lower the migration of young fish, and the causes which deterorganisms the nucleus does not seem to be concerned, as mine rapidity of growth. in higher organisms, in the blending, during fertilisation, Mr. G. L. Alward expressed his belief in the value of of two distinct lines of descent, but presides over the fish hatcheries, and also advocated the exploration of the nutritional activities of the cell, and fertilisation is replaced area between Norway and Iceland in the hope that new bs various nutritional devices.
i fishing ground may be found so as to relieve the present
strain on the resources of the Dogger Bank. Dr. Master- favourably received in this country, that the causal agent man and others advocated the attacking of special problems, in the disease invades the body through the skin, nor was and thought that the more general questions might be for a repetition of Plehn's experiment of feeding monkeys with the present postponed.
freshly discharged embryos attended with the slightest Systematic Study of Oceanic Plankton.
Habits of Tube-building Worms. Dr. G. H. Fowler put forward some suggestions for the Mr. Arnold T. Watson gave an account of the habits of more systematic study of oceanic plankton. Evidence that temperature appears to be the chief determinant in the dis- by means of its branchial tentacles, particles which are
tube-building worms. He showed how Sabella collects, tribution of plankton was cited, the highest depth of a applied by means of the collar lobes to the outside of a species being the position of its maximum, the lowest depth that of its minimum, temperature at any given against the intrusion of an enemy, the mouth of the tubur
mucous tube secreted by the epidermis. As a safeguard geographical position. It was urged that, for the solution of the problems demanding attention, oceanic expeditions the rock-boring species the end of the tube rolls up like
usually collapses when the worm retracts, but in one of should be confined to the systematic study of small areas
the frond of a fern. Terebella builds its tubes of sand. instead of making long voyages, that the upper zones of shells, or gravel, terminated by an arborescent arrangewater should be more carefully investigated than has
ment composed of single grains of sand or other suitable hitherto been the case, and that standard tow-nets should
material. Pectinaria produces the well-known conical be adopted internationally by all expeditions in order to
sand-tubes, the material for which is selected with great afford means of comparison of the fauna in different seas
Owenia constructs a flexible tube by attaching in and under different conditions.
an imbricating manner flat sand grains and fragments of
shell to a membranous tube secreted by special epidermal Life Cycle of the Protozoa.
glands. Panthalis weaves a massive tube composed of Prof. Calkins referred to some features in the life cycle of threads supplied by the parapodial glands. These tubes the Protozoa, and urged that the whole life cycle should are open at both ends, but the worm is defended from be worked out before a new species could be regarded as attack by a series of internal valves at each end of the safely established. This safeguard would prevent confusion tube, which are automatically closed by the inrush of sea and the undue multiplication of species.
water immediately the inmate of the tube retracts itself. showed, for example, that two such well-known and apparently fixed species as Paramoecium caudatum and aurelia
Papers on Lepidoptera. are no longer to be regarded as distinct. During the progress Prof. E. B. Poulton exhibited a series of forms of Acraea of a culture of P. caudatum, an individual appeared with all johnstoni, Godm., showing that each one of the protean the characters of P. aurelia (including form of body and series of varieties has been evolved in relation to a Danaine double micronuclei), but after forty-five generations, the or Acræine model, the models and mimics occurring organisms being watched daily, the aurelia characters were together on the slopes of Kilimanjaro. lost, and the entire race became P. caudatum again. In Dr. F. A. Dixey exhibited butterflies, some possessing any such life cycle the organisms pass through phases of an epigamic scent, others an aposematic or warning sceni. vitality comparable to the different age-periods of Metazoa. and others in which both kinds of scent existed indeThere are periods of (1) youth, characterised by great vigour pendently. It is well known that the male of Ganonis of cell multiplication ; (2) maturity, indicated by changes in napi
, one of our common white butterflies, exhales a fragthe chemical and physical balance of the cell, accompanied rant scent (compared to that of lemon verbena) which is by differences in size or protoplasmic structure, leading to i probably epigamic in significance. Dr. Dixey has found the formation of conjugating individuals, with or without | similar, though weaker, scents in the males of other British sexual differertiation; (3) in forms which do not conjugate, Pierinæ, Satyrinæ, and Lycænidæ, and many of the native old age or senescence, ending in death. In many forms, African species were also found to possess an agreeabir especially where dimorphic gametes are produced, the odour suggestive of chocolate, vanilla, or the scents of period of sexual maturity leads directly to that of old age, various flowers. These scents are generally distributed by and gametes which fail to conjugate soon die without specialised scales (androconia), the distribution being. to further multiplication, as in the majority of Sporozoa and some extent, under control, the perfume being economised in many Rhizopods. In Ciliata, although failure to con
when not needed in courtship. The offensive odours are jugate is finally fatal, many generations may be formed or less shared by both sexes, but are sometime before death occurs, and in these may be studied the stronger in the female, and generally occur in forms which. peculiar cytoplasmic changes which accompany protoplasmic on independent grounds, are believed to be protected. senility. While working at the maturation phenomena in These aposematic odours are usually perceptible even in Paramecium, Prof. Calkins and Miss Cull were able uninjured specimens, but are much more evident when the to show that the curious crescent form assumed by the thorax is crushed. micronucleus is the stage of synapsis, the chromosomes Mr. G. T. Porritt read a paper, full of details, on being double at this time, apparently by union side by side melanism in Lepidoptera. He pointed out that melaniser in typical parasynapsis. The two following maturation had increased with extraordinary rapidity in south-west divisions have not yet, however, been completely followed. Yorkshire and parts of Lancashire, and also occurred, ro The speaker also dealt with the subjects of fertilisation a less extent, in other parts of the United Kingdom In and parthenogenesis, pointing out that the latter has only
(e.g. Amphidasys betularia, Odontoptera a limited success, acting merely to postpone or counteract bidentata) the change has been sudden, but in most cas physiological death (Hertwig). Physiological and germinal there has been a gradual, though rapid, change from pale death in Protozoa are connected with exhaustion of vitality to black. More than thirty species are melanic in Yorkand of definite substances in the cell.
shire, most of which have become so during recent years
and there are other species which are tending in the same Infection of Monkeys with Guinea-worm.
direction. Many of these melanic forms will probably, ar Dr. R. T. Leiper described some results obtained by the no distant date, oust the ordinary pale forms. The variets infection of monkeys with guinea-worm. These confirm varleyata of Abraxas grossulariata has, however. not inthe view that Filaria medinensis gains access to the human creased, and, though known more than forty years ago, in host by introduction in the larval stage (while still con
as it was then, although melanism is so tained within its intermediate host, Cyclops) into the strongly impressed on the race that a brood reared this stomach in drinking water. The larvæ are released and vear from a pair of moths from wild larv.z. were all stimulated into activity by the gastric juice. A monkey the extreme dark form, no single example showing any which had been infected in this way was killed after six tendency towards the pale ordinary form. The reasons for months, and five guinea-worms--three unfertilised females and causes of the phenomenon were then discussed. The and two males (each of the latter 22 mm. long)—were usually accepted theory is that the darker colour rendera found. No experimental evidence could be obtained in sup- the insects less conspicuous as they rest upon the darkened port of the theory which has, during recent years, been (by soot, moisture, &c.) tree trunks, and, thereforr, mor