of the two races in the treatment of ornament differed so widely that in some pages of the "Book of Kells," for example, the two can be separated as easily as if they were of different colours. It is odd to find that Mr. Kermode describes the interesting crucifixion shown on p. 72 and here reproduced as "an example of pure Byzantine art." To our eyes it is nearly pure Celtic, and has no relation, artistically, to any Byzantine crucifixion we have ever seen. The statements, however, throughout the "Notes" are in general accurate and restrained, and there is an entire absence of the wild local enthusiasm so often found in books of this particular character. The "Notes" may be commended as likely to be of great use to anyone visiting the island or studying its antiquities.

MOLLUSCAN MORPHOLOGY.1

THIS fifth volume of the important "Treatise," edited by Prof. Ray Lankester, deals with the Mollusca, and is the work of the one biologist capable of doing this group most justice, namely, Dr. Paul Pelseneer. Like its predecessors in the series it treats of the subject almost exclusively from the morphological standpoint, just such a sufficiency of systematic matter being added as to justify the title, while it is, of course, very far from being, and indeed does not pretend to be, a manual on the phylum.

Some delay has occurred in its appearance, owing to the need of translation and revision for the press, which has been carried out by Dr. Gilbert Bourne.

em

FIG. 1.-Stenogyra mamillata, left side view, with four embryos in the ovi

duct. m, embryo. From "A Treatise on Zoology."

The work itself is an expansion of Dr. Pelseneer's similar contribution to Blanchard's "Traité de

Zoologie." The translation is remark

ably well done, and save in some of the opening sentences it

is hard to realise that it was not written in English. Not but that there are small slips such as "biannual for "biennial." The revision, we suspect, has largely consisted in the importation of new terms, so dearly beloved of a certain school of biologists, that do not altogether make for clearness, and are foreign to the lucid style customary in the author's other writings. The opening paragraph on the "general description and external characters" of the Mollusca (p. 3) is a case in point. While the statement (p. 20), "It has been shown that in the Cephalopoda hyperpolygyny is the rule, and in certain Atlanta and American Unionida, hyperpolyandry," inspires the not hypercritical comment that, without hyperbole, it is hypertechnical. Certainly a glossary will be indispensable

to the work.

One is glad to observe that that mythical monster, the "Archi-" or "Schematic Mollusc" has dwindled to a shadow of its former self, and now survives solely in a diagrammatic figure as a "scheme of a primitive mollusc" (Fig. 19). For, as Verril pointed out in 1896 (Amer. Journ. Sci., series iv., vol. ii., pp. 91-92), the primitive mollusc is rather to be sought in the early larval stages, such as the Veliger form. Even now one is tempted to think that the "primitive" has been introduced by the translator, since the author in his previous work, to which reference has already been

"A Treatise on Zoology." Edited by Dr. E. Ray Lankester, F.R.S.

Part v, Mollusca, by Dr. Paul Pelseneer. Pp. 305: 301 text illustrations. (London: A. and C. Black, 1906.) Price 155. net.

made, simply labels his figure "Schème d'un Mollusque," which is rather a different thing.

Dr. Pelseneer's explanation of the torsion of the gastropod body evidently now meets with Prof. Lankester's approval, for it is the only one advanced and is reinforced by an additional diagram.

A good deal more attention is paid, and rightly, to the shell than in the author's previous writings, and it is interesting to see Sharp's theory of the progressive disappearance of the anterior adductor muscle in certain successive forms of Lamellibranchs (which was first illustrated by specimens in the Index Hall of the Natural History Museum) made the subject of illustration, though in the text this disappearance is made the cause, instead of the consequence, of the alteration of the body-axis.

One or two other points need further attention. Allusion might advantageously have been made to the origination of the gill in Cyclas, Teredo, and Scioberetia by perforation of a continuous membrane: also to the discovery by Dall that Philobrya passes through glochidium

a

stage, which is

therefore not confined to the Unionidæ.

The systematic portion is open

to

much criti

cism. It does not differ materigiven in Dr. Pelally from that seneer's previous works, though there is, so to speak, some shuffling of the cards. It is a great pity, however, that the no

menclature has

not been brought up-to-date. This would have prevented such an error as recording Zonites British.

as

FIG. 2.-Nautilus macromphalus creeping on a horizontal surface, anterior view. a, o, t, anterior ophthalmic tentacle; e, eye; ho, hood; in, infundibulum; pa, nuchal part of the mantle; p, o, t, posterior ophthalmic tentacle; sh, shell. (After Willey.) From "A Treatise on Zoology."

of the illustraThe majority tions, which are all clear and well printed, are diaof the few pictorial ones grammatic, or elucidate structural features, while most are those used by Owen, without acknowledgment of their source, in his article on Mollusca in the eighth edition of the Encyclopædia Britannica. The greater number of these are now, very properly, attributed to their rightful authors, but of those still labelled "From Lankester after Owen" it has escaped observation that Nos. 71, 134, and 136 are after Adams, No. 158 after Philippi, and Nos. 66 and 135 are from S. P. Woodward's "Manual," while the Férussac and D'Orbigny's "Histoire." well-known figure of Sepia officinalis (No. 299) is from

The index would have been more useful had refermatic parts been included. ences to the genera cited elsewhere than in the syste

All these are, however, minor points, and the fact remains that malacologists now possess one of the best-written treatises yet produced in the English language on the morphology of the Mollusca.

(B V)2.

ΤΗ

the "

44

CYCLES IN CHRONOLOGY.1 HAT the 1260 years understood to be expressed by time, times, and a half" (taking "time to indicate a prophetic year of 360 days each) of Dan. xii. 7, and repeated in Rev. xii. 6 and in Rev. xi. 2 and xiii. 5 under its equivalent term forty and two months (taking a month as thirty days), was in fact an astronomical cycle, was first suggested by Loys de Chéseaux in a work published at Paris in 1754, three years after the author's death. But it did not meet with much attention in England until a small work on the subject was published by Mr. W. Cuninghame in 1834, and it was subsequently more fully explained by Mr. H. Grattan Guinness in his Approaching End of the Age," which appeared in 1878.

Dr. Bell Dawson however, in a pamphlet now before us, goes into the matter much more elaborately, using the most recent knowledge of the lengths of the solar and lunar years (by lunar year he means twelve lunar synodic months or lunations), and finds a remarkable correspondence between multiples of these which coincide with those of the number in Daniel. As seven is a perfect number in Scripture, and Daniel mentions three and a half prophetic years ("time, times, and a half "), he thinks that the 1260 must be doubled, which makes 2520 lunar years. Now a lunation contains, according to the most modern determinations, 29.530589 days; 504 of these are equal to 178,601 days and 2520 to 893,005 days within about four minutes. An eclipse-cycle is also pointed out, i.e., that 649 solar years are almost exactly equal to 8028 (223 × 36) lunations (the former amounting to 237042.1853, and the latter to 237042-0355 days), which is much more accurate than the Metonic cycle.

Dr. Bell Dawson carefully notes the different values which have been found (observationally and theoretically) for the secular acceleration of the moon's mean motion; but he seems to have forgotten that though probably constant or nearly so in amount, its effect, when long periods of time are taken into account, varies like the accelerating force of gravity, as was pointed out by Halley, its discoverer, according to the square of the number of centuries. As Chéseaux had done before him, he shows the astronomical significance of the cycle 2300 years in Dan. viii. 14, as well as that of the 1260 years before spoken of; but he treats it somewhat differently. Chéseaux (whose scheme, we may mention, is explained in the second volume of Mr. Chambers's “ Handbook of Astronomy") took the difference between 1260 and 2300 (i.e. 1040) years, and showed that 1040 solar years form a period almost exactly equal to 12,863 lunations, the former amounting to 379851.8839 and the latter to 379851.9624 days. But Dr. Bell Dawson takes them as lunar years (or periods of twelve lunations) and shows that 1780 (the mean between 2300 and 1260) lunar years is almost precisely equal to 1727 solar years, each exceeding 630773 days by only 0.27 and 0.37 respectively, and therefore differing from each other by only 0.10 of a day in that time or about 0.006 in a century. It does not appear that any reference is made to the 1290 and 1335 days of Dan. xii. 11 and 12. No attempt is made to discuss the terminus à quo (or therefore ad quem) of Daniel's periods, being beyond the scope of the paper before us, which treats only of the numbers themselves and their accordance with astronomical epochs.

Dr. Bell Dawson inserts a reflection on the inferior accuracy of the Roman calendar arrangements to those of the Chaldeans and other Oriental nations. It is probable, however, that when Julius Cæsar re

1 "Solar and Lunar Cycles implied in the Prophetic Numbers in the Book of Daniel." By Dr. W. Bell Dawson. Pp. 20. (From the Transactions of the Royal Society of Canada, vol. xi., Section 3.)

formed the calendar he decreed that each fourth year should be an intercalary year, not because he was not aware that the actual length of the year was some what less than 365 days (a question which had been discussed by Sosigenes, who assisted him), but because he thought it would be a convenient rule and sufficient for all practical purposes. In this a distinguished astronomer of our own day (Prof. Newcomb) agrees with him; and indeed the chief object of the introduction of the Gregorian calendar was to bring back the date of the vernal equinox to that which it had at the epoch of the Council of Nicæa. W. T. L.

PREVENTABLE DISEASE AND MILITARY STRENGTH.

Na letter to the Times (June 6), Mr. St. John IN Brodrick directs attention to the serious diminu tion in the military strength of an army, not to say the terrible loss of life, which ensues in campaigns from diseases which are largely preventable. It is a truism, well recognised by medical men, that the soldier has much more to fear from the ravages of disease than from the bullets of the enemy. Mr. Brodrick points out that

"In South Africa the deaths per 1000 were 69 from disease and 42 from wounds, but the admissions to hospital were 746 per 1000 from disease and 34 from wounds. In other words, about 450,000 were passed through the occurred, while the admissions for injuries in action were hospitals for disease during the war, and 14,800 deaths only 22,000.

"

Dysentery and enteric fever are the great scourges of an army in the field, and, as was pointed out in an article in NATURE (lxxii., p. 431), are largely preventable. That this is the case is proved by the records of the Russo-Japanese War, in which the Japanese had a total of some 221,000 killed and wounded and 236,000 cases of sickness, a ratio very different from that which obtained in our own army in the Boer War. The Japanese have realised to the full the importance of hygienic measures in the field; sanitary corps went on ahead of the main army and chose the camping grounds, supervised the water supplies, and exercised a rigid sanitary control in all matters, with the above result.

Mr. Brodrick suggests one simple remedy :

"Why should not the admirable body of Army Medical officers who have made sanitary conditions a study educate combatant officers in the elements of military hygiene? Every cadet at Sandhurst or Woolwich should be examined on passing out in a problem which he should grasp as easily as tactics or strategy, since upon it the fighting strength by which he is to win his battles depends. captain before promotion to major might be encouraged to get a special certificate which would excuse him from all such training at the Staff College."

Sir Frederick Treves, in a letter to the Times, cordially supports this suggestion, and goes further. advocating that a like knowledge of a more elemen tary character should be possessed by the private soldier.

In addition it may be added that the formation of a sanitary corps seems desirable to aid the medical staff, to guard and control the water supplies, and the like. At present the Army Medical officer is powerless to enforce sanitary measures; although responsible, he can give no orders, and can only act through a commanding officer, often junior to himself, who has no technical knowledge. Moreover. through the Esher Committee, the Director-General. who formerly had direct access to the Secretary of State and had a seat on the Army Council, has been

deprived of those privileges, the Adjutant-General at present being practically head of the Medical Department. Now that a former Secretary for War has directed public attention to the matter, it is to be hoped that those in authority will recognise that medical science is a vital part of military strength, a dictum which has for years been preached by the medical profession.

NOTES.

At the meeting of the council of the Royal Astronomical Society, held on Friday last, June 8, the following resolution was unanimously agreed to:-"That the council learn with deep concern of the danger threatened to the Royal Observatory, Greenwich, from the erection of a large electric generating station near the observatory; and desire to represent to the Admiralty at the earliest opportunity their conviction of the paramount importance of maintaining the integrity and efficiency of Greenwich Observatory, which has been adopted as the reference point for the whole world." It was further resolved that a copy of this resolution be forwarded to the First Lord of the Admiralty.

MR. HALDANE, M.P., Secretary of State for War, will open the electrical laboratory of the National Physical Laboratory on Monday, June 25, at 2.45 p.m.

Ar the twenty-fifth annual meeting of the Royal Society of Canada, recently held at Ottawa, Dr. William Saunders, the director of the Dominion Government's system of experimental farms, was elected president for the ensuing year, with Dr. S. E. Dawson vice-president.

INVITATIONS have been issued by the Institution of Electrical Engineers for a conversazione at the Natural History Museum on Tuesday, June 26, to meet the visiting delegates

from kindred institutions.

PROF. K. BIRKELAND, of Christiania, the inventor of the only successful commercial process for obtaining nitric acid by the direct oxidation of atmospheric nitrogen, will read a paper before the Faraday Society about June 26 entitled Oxidation of Atmospheric Nitrogen by Means of the Electric Arc."

MUCH interest was aroused in India some time ago in the attempt to introduce the permanganate treatment of snake-bite. In the Central Provinces a large number of Sir Lauder Brunton's lancets were distributed last October for use by vaccinators and selected landholders. Several cases of successful treatment have been reported to Government, but unfortunately, says the Pioneer Mail, none of the reports gives sufficient detail to prove that the bites were really those of poisonous snakes, and it is therefore not possible to form any conclusions as to the value of the treatment.

A PARTY of Birkbeck College zoological students spent Whitsuntide at West Mersea, near Colchester, collecting marine specimens. Owing to the low temperature of the surface waters the tow-netting expeditions were not very productive, but many and varied forms of life were brought up by the trawl and the dredge.

THE annual conversazione of the Royal Geographical Society will be held at the Natural History Museum tomorrow evening, June 15.

A TELEGRAM from Reggio di Calabria states that fairly strong earthquake shocks were felt there on June 10 at 2.30 a.m. and 9.45 a.m. At Monteleone, Calabria, two strong shocks were felt at 2.45 a.m.

PROF. W. F. KOHLRAUSCH, of Hanover, will be the president of the Verband deutscher Electrotechniker for 1906-8.

DR. BERNHARD MOHR, of London, recently presented to the museum of the German Chemical Society 100 letters written by the famous Liebig to Dr. Mohr's father, the late Prof. Friedrich Mohr, of Bonn, during the years 1834 to 1869.

DR. STUTZER, assistant in the geological institute of the Freiburg (Saxony) Mining School, has been awarded a grant of 2000 marks by the committee of the Carnegie fund to enable him to continue his investigations on iron deposits in Lapland.

PROF. LUDWIG BOLTZMANN, the well-known professor of theoretical physics in the University of Vienna, has been awarded the prize of the Peter Wilhelm Müller fund of Frankfurt a.M. The award consists of an appropriately worded gold medal and 9000 marks, and is made to the most brilliant workers in pure science.

AT the seventy-eighth meeting of the Deutscher Naturforscher und Aerzte, which will be held this year on September 16-22 in Stuttgart, there will be an exhibition of scientific and medical appliances and subjects as in previous years. The König Karls Hall of the Königlicher Landesgewerbemuseum has been set apart for the purpose. All announcements and communications may be addressed to the president of the exhibition committee, Dr. Lampert, Archivstrasse 3, Stuttgart, from whom further particulars may be obtained.

PROF. WALTER NERNST, professor of physical chemistry in Berlin, has declined the opportunity of proceeding to Leipzig as the successor of Prof. Ostwald, whose resignaformerly a privatdocent at Leipzig from 1889 to 1891, when tion will take place on September 30. Prof. Nernst was he accepted a professorship in Göttingen University. According to the Physikalische Zeitschrift, Prof. Ostwald's successor is to be Dr. K. Haussermann, professor of technological chemistry and director of the applied chemistry laboratory of the Technical High School, Stuttgart. A SPECIAL meeting was held in the Great Hall of the University of Athens on May 20 to celebrate the fortieth anniversary of Dr. A. C. Christomanos's appointment as professor of chemistry in the University. A large audience, including the Greek Minister of Education, the University professors and students, and many of the general public, was present. Dr. A. C. Dambergis, the professor of pharmaceutical chemistry, referring to the great work which Prof. Christomanos has done in the forty years, asserted that the greatest has been the pioneer work in the introduction of scientific chemistry into Greece with the provision for laboratory work in chemistry and the other sciences, and more particularly in organising so successfully the large chemical department of the University with its laboratory accommodation for 130 students.

Prof. Christomanos was the recipient of numerous honours, including several from foreign countries.

DR. RUDOLF KNIETSCH, the director of the Badische Anilin- und Soda-Fabrik, died on May 28 at the early age of fifty-two. From the éloge dedicated to Dr. Knietsch s memory by the Badische Anilin- und Soda-Fabrik, we learn that Dr. Knietsch was born in 1854 in Oppeln, in Schlesien. From 1876-1880 he studied at the Technical High School in Berlin, and graduated in 1881 at Jena University. He was for a short time an assistant in Dr. Emil. Jacobsen's private laboratory, and in 1882 entered the Farbenfabrik von Bindschedler und Busch in Basle,

where he worked at the nitration of dichlorobenzaldehyde and the preparation of chloroindigo. In 1884 he joined the Anilin- und Soda-Fabrik. He founded in 1888 the industry of liquid chlorine, and devoted himself with zeal to the task of modifying the Winkler process of preparing sulphuric anhydride. Knietsch read an important communication on the results of this work before the German Chemical Society in 1901. For the solution of the problem of the commercial preparation of synthetic indigo Dr. Knietsch proved himself to be the right man in the right place. In company with a number of earnest colleagues he worked out and developed the present manufacturing processes for the preparation of the materials necessary for the synthesis of indigo and other dyes. Always broadminded, he was ready at any time to replace existing plant and methods by improvements. In 1904 Knietsch was placed at the head of the firm. The Verein deutscher Chemiker, at the annual general meeting in Mannheim in 1904, awarded the Liebig gold medal to Dr. Knietsch, and at the opening of the new Technological Mechanical Institute of the Dresden Technical High School in 1905 the honorary degree of Dr. Ing. was conferred on him.

. THE weekly weather report issued by the Meteorological Office for the period ending June 9 shows that the present month has opened with typical summer weather. The major portion of the United Kingdom was entirely rainless, the only rains reported occurring in parts of Scotland and Ireland, and amounting only to few hundredths of an inch. Bright sunshine was for the most part greatly in excess of the average, So per cent. of the possible duration occurring in the Channel Islands and 71 per cent. in the south of England. The temperature averages were generally rather low, and in the south of England the sheltered thermometer at night fell below the freezing

point.

WE learn from the Journal of the Society of Arts that what can be done by sanitation to stamp out malaria is shown by Mr. Consul Morgan in his reference (No. 3565, Annual Series) to the work of the Italian Red Cross Society during late years to stamp out malaria in the Roman Campagna. The first attempt was made in 1900, when the returns showed that not less than 31 per cent. of the inhabitants of the " Agro Romano had been feverstricken. In 1901 the figure was returned at 26 per cent., 20 per cent. in 1902, 11 per cent. in 1903, 10 per cent. in 1904, and 5.1 per cent. during last year. These results were obtained by strict sanitary measures, use of wire nets so as to prevent access of mosquitoes to cottages, and free distribution of quinine among the peasantry.

THE annual dinner of the London section of the Society of Dyers and Colourists was held on May 23, when a representative company was presided over by Sir Thomas Wardle, president of the society. In proposing the toast of the London section of the society, the president expressed his astonishment at the beautiful work being done in the dyeing industry in Italy, and how much pure chemistry is being made use of in that work. London, he continued, is taking an interest in chemical development, and he suggested that the Dyers' Company might associate itself in some way with such a body as the Society of Dyers. Sir Thomas Wardle concluded his address by appealing to the younger men to take advantage of the splendid scientific training now available, and to induce others to do the same, for by such methods many of our lost industries would be won back. Responding to the toast of the "Allied Industries," Dr. J. C. Cain said no doubt to some

extent our patent laws, the lack of cheap alcohol, and other causes have had a certain amount of influence in the downfall of the English aniline dye industry, but in his opinion the only real cause has been the lack of a man of commanding genius, like Perkin or Nicholson, who could discover a colour, make it, and sell it. Prof. R. Meldola, F.R.S., in proposing "The Visitors," remarked that we have lost tone in our supremacy in this branch of manufacture, but the blame is not on the shoulders of the dyers, who have always been on the qui vive to utilise new discoveries It was the English and Scotch dyers who first took up chemical dyes and encouraged the manufacturers to proceed. Mr. F. Robinson proposed "The Chairman," and directed attention to the fact that presentday results and modern methods could never have been attained but for the research chemists and their work. At one time dyeing was more an art than a science; now our chemists have made it practically a science. The old dyestuffs such as indigo and madder are gradually and surely disappearing, and are being supplanted by synthetic products. The English dyeing and colouring industry is moving with the times, and will eventually hold its own against all rivals.

We have received a copy of No. 12 of the fifteenth volume of the Zeitschrift für Oologie und Ornithologie, said to be the only serial in the world specially devoted to the interest of the egg-collector. The present part contains notes on the eggs of two African birds previously unknown to collectors, general observations and suggestions on subjects intimately connected with oology, and descriptions of certain eggs from Turkestan.

IN the report for the year 1905, the committee of the general progress of that institution and the present state of Albany Museum, while referring with satisfaction to the

the collections, directs attention to the congested state of the buildings, and the urgent need for more space and for additional funds, if the work is to be carried on in an effective manner. The appointments of Profs. Duerden and Schwarz to the zoological section are stated to have been followed by most satisfactory results.

IT has been stated by those who have investigated the subject in the selachian group that fishes lack lymphatic vessels other than those of the visceral system, the superficial and deep-seated vessels of the heart and trunk being regarded as veins, and their sinuses as venous sinuses. However this may be in the case of sharks, Mr. W. F. Allen, in a paper on the lymphatics of the loricate fish Scorpænichthys, published in the Proceedings of the Washington Academy (vol. viii., pp. 41-90), shows that it is not so in the case of the group to which the latter belongs. On the contrary, Scorpænichthys has as fully developed a lymphatic system as any vertebrate, so that it may be said that in general wherever connective tissue exists there lymphatics will be found.

THE February and March issues of the Proceedings of the Philadelphia Academy contain a paper by Mr. J. A. G. Rehn on tropical American grasshoppers of the group Acridinæ, with descriptions of several new forms, and likewise the commencement of one by Dr. R. Smith on the phylogeny of the races of a species of gastropod of the Eocene genus Volutilithes. In the case of the genus Fulgar, it has been supposed that certain Miocene forms represented the ancestral stock of the living American species. According to the author this is not so, the fossil forms being decadent senile offshoots from the original line, which appear, however, to be dominant. A very similar

state of affairs is shown to exist in the case of Volutilithes, with the important exception that the main ancestral line is the one which is dominant.

THE Ostracoda of the San Diego region (No. 1), the California shore-anemone, Bunodactis xanthogramma, and sexual dimorphism in the hydroid polyps of the genus Aglaophenia, form the subjects of articles nine, ten, and eleven of Contributions from the San Diego Marine Laboratory issued in vol. iii. of the Zoological Publications of the University of California. In the article on dimorphism (by Mr. H. B. Torrey and Miss Martin) it is shown that in the genus mentioned, not only are the gonophores dimorphic, but an analogous dissimilarity also obtains in the jointed plumose structures known as corbulæ, of which numerous examples are figured. The plate intended to illustrate Mr. Torrey's paper on the sea-anemone was destroyed in the San Francisco fire, but a new one will be supplied later.

THE April issue of Spolia Zeylanica is of more than usual interest. It opens with a translation of an article by Dr. F. Doflein, of Munich, entitled "Termite Truffles," being the description of certain remarkably nodular masses of fungus cultivated in their nests by white ants in Ceylon. The hillocks of these termites were found by the author to contain a number of large chambers, each approximately the size of a cocoanut, and each containing one or more large friable masses, looking somewhat like small bathsponges. These cakes were occupied by thousands of termites, ensconced in the cells and connecting passages. The framework of each was beset with numerous white nodules of the size of pins' heads, which proved to be fungus-growths. These nodules are eaten by the larvæ of the workers and soldiers and by the sexual forms at all ages, the adult soldiers and workers having, however, other food. That the funguses are introduced and cultivated by the termites seems undoubted. In the same publication Dr. A. Willey records a singular instance of symbiosis in a crab, originally described from Mauritius under the name of Melia tessellata. When first described its habit of holding sea-anemones in its two front claws was not noticed, but although this was observed later on in Mauritius, it has been generally overlooked. According to Dr. Willey's account and figure, the crab holds in each claw a small white anemone, which it presents, with the tentacles fully expanded, to every intruder, in "true boxing attitude." The ground-colour of the crab is whitish with a rosy flush on the front of the shell, which has also a pattern of black lines. Probably both crab and actinians benefit by the association, the actinians enjoying increased mobility, and the crab sheltering and defending itself with the living gloves with which it is provided." In the author's opinion, the stinging threads of the anemone are the active means of defence and offence.

66

A LEAFLET, No. 16, published by the Department of Agriculture in British East Africa, contains the reports on various samples of cotton grown at Golbanti and Malindi. The cotton was produced from Egyptian Afifi seed, except for one sample of Sea Island and one of American upland. The soils on which the crops were grown were a heavy alluvium or a lighter red soil, the latter yielding much better results, owing probably to its requiring less cultivation. The values, except for the Sea Island, ranged between fivepence and sixpence per pound. There is a striking difference between the yield from Egyptian seed on the red soil and the other crops obtained.

THE green colour of plants is such an ever-present reality that the explanation is apt to be overlooked. The absorption spectra of chlorophyll and the curves of absorption and assimilation do not directly furnish a solution, and it is only from the consideration of these, together with the effects produced by the absorption and dispersion of light rays in the atmosphere, that a satisfactory explanation is obtained. The subject is ably discussed by Prof. E. Stahl in Naturwissenschaftliche Wochenschrift for May 6, where he points out that the two pigments contained in chlorophyll are suited to the sun's rays as modified by reflection, the colours being complementary to those of the chlorophyll-absorbing rays that predominate in diffused light, and that certain rays, e.g. the ultra-red, are excluded wholly or in part owing to the danger of too great absorption in direct sunlight.

THE fungus Phycomyces nitens is well adapted to physiological investigation owing to the rapidity of its growth and its sensibility to stimuli. Proceeding out of investigations by Elfving wherein curvature of the sporangio

FIG. 1.-Phycomyces nitens stimulated to grow towards and over the surface of a porous pot.

phores was attributed to physiological action through space, Prof. L. Errera was led to experiment on the curvatures caused by the presence of various substances such as rough and polished metals, porcelain, glass, deliquescent salts, marble, mica, &c. The results so obtained, and the notes relative to them, had been sufficiently fully drafted before Prof. Errera's death to allow of publication, and they appear in Recueil de l'Institut botanique, Brussels, vol. vi., 1905. It was found that Phycomyces curves towards bodies that absorb moisture and away from those that give off vapour. Thus the sporophores curve towards an unpolished rod of iron, but not towards a piece that is perfectly polished. A number of photographs accompany the paper, of which one of the most striking is reproduced. A dry, porous pot is suspended over the Phycomyces growing on bread in a moist atmosphere. The pot absorbs moisture, and the sporophores have curved right over the surface of the pot, some of them ultimately turning upwards owing to the stimulus of gravity.