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that with no further elaboration of the furnace than on averages, approximations, graphs, elementary a short firebrick arch at the fore-part (illustrated in mensuration, and logarithms. This portion of the Fig. 15) they will perform their work very efficiently, book might well have been extended even at the and with practically no smoke when using a bitu- expense, if necessary, of some of the chapters relating minous coal.

to purely business matters. But the subjects treated A chapter is devoted to the chemistry of the com- are very numerous, affording considerable ground bustion process. In referring to the hydrogen in fuels, for selection, and many teachers will no doubt, and the statement occurs, “it is generally assumed to be with advantage, omit some of the technical compresent combined with carbon to form hydrocarbons. mercial chapters. At every stage examples are The most important of these for the fuel user are introduced in great abundance, the

to -methane, ethylene and acetylene.” A small amount which extend to nearly fifty pages. The book conof at least the first may be present in coal, but are we cludes with a collection of test papers, and a large to assume the authors to mean that these are the number of miscellaneous problems. Parts i. and ii. important hydrocarbons existing in the coal before it are published separately, and also in one volume. The has been heated ?

examples and answers may also be obtained without In view of Bone's work (mentioned in a short foot- the other text. Altogether the book is one that denote) it is a pity the authors did not revise their theory serves, and will doubt obtain, extended to account for the formation of smoke, seeing that the circulation. book was not published until a twelvemonth after Bone With the issue of part vi. of Messrs. Hall and and Wheeler's paper appeared in the Journal of the Stevens's “ School Geometry,” this popular text-book Chemical Society (August, 1903), and Armstrong's must now be nearing its completion. The present paper in the same number, in which it is definitely section corresponds, substantially, with Euclid, Book stated " neither hydrogen nor carbon being burnt xi., 1-21, and it further deals with the mensuration of preferentially."

J. S. S. B. the simpler geometrical solids. In establishing the

theorems of pure solid geometry, the authors follow

Euclid rather closely, but there are some useful addiSCHOOL MATHEMATICS.

tions. Thus it is shown how a point in space is located New School Arithmetic. Part ii. By Charles Pendle- by means of rectangular coordinates; but it is not

bury, assisted by F. E. Robinson. Pp. vi +207 to shown how position and form may be exhibited 468 + xliv. (London : George Bell and Sons, 1904.) | graphically by means of projections. In dealing with Price 25. 60.

areas and volumes, elementary trigonometry is used. New School Arithmetic. By Charles Pendlebury,

The prismoidal formula is also introduced, but its value assisted by F. E. Robinson. Pp. xvii + 468 + xliv.

is scarcely made sufficiently manifest, and it is not (London: George Bell and Sons, 1904.) Price 4s. 6d. shown how to deal approximately with irregularly New School Examples in Arithmetic. By C. Pendle-shaped figures, by means of Simpson's or other rules.

bury, assisted by F. E. Robinson. Pp. xiii +223+ The book is printed in very distinct type, and the xliv. (London: George Bell and Sons, 1904.) figures and diagrams are beautifully designed and

executed. The subject-matter is presented and deA School Geometry. Part vi. By H. S. Hall and

veloped in the clear and attractive style which is always F. H. Stevens. Pp. iv +347 to 442+iv. (London : found in the authors'text-books, and is illustrated by

Macmillan and Co., Ltd., 1904.) Price is. 6d. well chosen examples.
Theoretical Geometry for Beginners. Part iv. By Part iv. of Mr. Allcock's “ Theoretical Geometry for
C. H. Allcock. Pp. 224. (London: Macmillan and

Beginners treats, in the first instance, of ratio and Co., Ltd., 1904.) Price is. 6d.

proportion, with geometrical applications. The proElementary Plane Geometry. By V. M. Turnbull. positions correspond roughly with Euclid, Book vi., Pp. vi + 136. (London: Blackie and Son, Ltd.,

but the style of proof is different. The reader is first 1904.) Price 2s.

introduced to the conception of ratio and proportion by Jathematical Problem Papers. By the Rev. E. M. means of numerical and algebraical examples, and his Radford. Pp. vi + 203 (Cambridge : University knowledge of arithmetic and algebra is drawn upon Press, 1904.) Price 45. 6d. net.

in establishing some preliminary theorems, which are ART II. of Messrs. Pendlebury and Robinson's subsequently used in demonstrating the various

" New School Arithmetic " has followed quickly theorems. The latter half of the book is devoted to on the publication of part i., and this excellent text-modern geometry, including chapters on harmonic book is now complete. The second part is concerned pencils, the complete quadrilateral, poles and polars, mainly with the application of arithmetic to the trans-centres of similitude, inversion, maxima and minima, actions of commerce, dealing with such subjects as and envelopes. Some numerical examples are given interest, discount, commission, stocks and shares, profit at intervals, but, as the title implies, the propositions and loss, &c. Ratio and proportion find a place, and and the exercises thereon are almost entirely confined they are illustrated largely by this class of problem. to deductive geometry, and from this point of view the The authors devote a little space to the training of treatment is eminently satisfactory. The book is got youths in computations suitable to experimental work up and printed in a way that leaves nothing to be in the laboratory. Thus we find that algebraical desired. symbols are freely introduced, and chapters are given The “ Elementary Plane Geometry" by Mr. Turn

Price 38.

PART

Pp. 39

bull is intended for youths who have already had a compass of much information concerning not only course of experimental geometry, and is almost entirely diagnostic characters of species, varieties, and forms, devoted to demonstrative geometry. It is divided into but also concerning their nomenclature, distribution, four sections, dealing respectively with triangles and and phenology. To illustrate the method of treatment

adopted by the author, Populus alba may be selected quadrilaterals, circles, areas, and with ratio, propor- from the twenty-three species of Populus considered tion, and similar figures. Most of the propositions in this work. Three varieties of this tree are contained in the volume belong to Euclid, but the sufficiently described as regards their distinctive author has allowed himself that freedom of treatment features; figures are given of resting-buds, twigs and that is now happily prevalent. The book shows no their transverse sections, four forms of leaves, flowers, conspicuous merits such as would render its general as to the times of flowering, of Aushing of the vege

seed, embryo, and seedling; information is tendered use either likely or desirable.

tative buds, and of fruiting, also as to the germinIn the volume by the Rev. E. M. Radford, the ation, distribution, and age attained by this species; author has compiled and arranged a hundred test or and finally hybrids including this species are noted. examination papers, each containing twelve problems; In so thorough a work it is exceedingly difficult to a large number of the latter are stated to be original, but the solitary one that the reviewer has observed is

avoid making statements not universally applicable, and many are taken by permission from published to the effect that Carpinus Betulus has a trunk with a examination papers. The collection is “intended light grey coating of cork. The work may be strongly primarily for the use of candidates for mathematical recommended to all engaged in the study of dicoty. entrance scholarships at Oxford and Cambridge,” and ledonous woody plants growing in the open in this the subjects on which problems are set comprise “pure country.

Percy Groom. geometry, algebra, trigonometry, analytical conics, The Cancer Problem in a Nutshell. By Robert Bell, and elementary mechanics,” with the addition in the

M.D.

(London: Baillière, Tindall and last fifty papers of elementary theory of equations and

Cox, 1904.) Price is. net. elementary differential calculus. The book will no doubt prove useful to the class of student for whom of malignant disease to a withdrawal of some con

Dr. Bell in this pamphlet ascribes the development it is intended, but the problems show no sign what- trolling influence exerted by the thyroid gland upon the ever of having been influenced by the reform in the cells of the body, caused by some toxic state of the teaching of mathematics which is now in progress. blood. He therefore advocates the administration of The author hopes shortly to publish a volume of solu- thyroid gland or of its active principle in the treatment tions, and this will be very acceptable to teachers who of the disease, and claims to have obtained successful

results. Little or no evidence is given in support of may use the work.

these views, and since malignant disease occasionally, though unfortunately rarely, undergoes spontaneous

cure, the apparent success of any form of medical treatOUR BOOK SHELF.

ment has to be carefully controlled before such a result

can be admitted. Dr. Bell's suggestions for the preHandbuch der Laubholzkunde. Charakteristik der invention of malignant disease may be of some value. Mitteleuropa heimischen und im Freien angep

R. T. H. flanzten angiospermen Gehölz-Arten und Formen mit Ausschluss der Bambuseen und Kakteen. By Photography on Tour. Pp. 132. (London : Published Camilto Karl Schneider. Erste Lieferung, pp. 160 ;

for the Photogram, Ltd., by Dawbarn and Ward, Zweite Lieferung, pp. 161-304. (Jena : Gustav

Ltd., n.d.) Price is. net. Fischer, 1904.) Price 4 marks for each Lieferung.

In these pages, the sizes of which are only 34 inches These two parts form the commencement of a work by 48 inches, we have a number of useful hints and intended to render possible the identification of the instructions which are well worth an amateur's time hardy species of angiospermous trees and shrubs in- to read. When the photographer is away from his digenous to, or cultivated in, Central Europe. Such base, and has to invent all sorts of makeshifts, he may a work invites comparison with Koehne's well known find 'many a useful wrinkle given here for which he book on the same subject rather than with the more comprehensive descriptive works by Koch and Dippel. brought into a very small compass a great deal of in

may later be very thankful. The author seems to have From the first named it differs in the vastly greater formation covering a wide field, and this pocket book number of illustrations, and in the fuller details given for the touring photographer should serve a useful regarding the characters of buds and twigs. These

purpose. additional details contained in Schneider's book go far towards removing the uncertainty of diagnosis involved in the provisional identification by means of the dicho The Story without an End. From the German of tomous keys employed throughout the work. The

Carové. By Sarah Austin. Illustrated by Paul present Lieferungen, dealing with the Salicaceæ,

Henry. Pp. vii + 77. (London : Duckworth and Myricaceæ, Betulaceæ, Fagacea, Ulmaceæ, Moraceæ,

Co.) Price is. 6d. net. l'rticaceæ, Santalaceæ, Loranthaceæ, Aristolochiaceæ, In this allegory a child is introduced to the beauties Polygonaceæ, Chenopodiaceæ, Phytolaccaceæ, Caryo- of plants, birds, insects, and other forms and aspects phyllaceæ, Trochodendraceæ, Ranunculaceæ, Lardiza- of nature. It pleases children to imagine themselves balaceæ, and some species of Berberis, nominally in close communion with inanimate nature, and they include 197 illustrations, but in reality contain

have no difficulty in endowing all the objects around quite 2000 figures of buds, twigs, leaves, in- them with human attributes. Poetic feelings, and fiorescences, flowers, fruits, and their parts. In sympathetic interest in plant and animal life, are addition, the free use of abbreviations and of small appealed to by this daintily bound and gracefully illusprint has rendered possible the condensation into small trated contribution to literature.

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LETTERS TO THE EDITOR.

find any good specimens, capable of being photographed,

showing the conversion of Zooglæa masses into Monads, [The Editor does not hold himself responsible for opinions although I many times saw and photographed Monads expressed by his correspondents. Neither can he undertake

originating from the pellicle as discrete motionless corto return. or to correspond with the writers of, rejected

puscles-especially when the infusions were kept at manuscripts intended for this or any other part of Nature.

temperature of about 72° F. (22° C.).' But one day last No notice is taken of anonymous communications.] month, on October 19, desiring to make certain observOn the Origin of Flagellate Monads and of Fungus.

ations, I made a weak infusion from a portion of a small germs from Minute Masses of Zooglæa.

handful of hay gathered in Norway more than two months

previously, which had since been kept in a small cardboard BACTERIAL scums are exceedingly common in ditches and box. The infusion was prepared and filtered in the manner ponds, nature's laboratories, and it is a matter of much already indicated, and divided into two portions : one, which importance to know what goes on therein. Some light may we may name A, being placed in a small open beaker and be thrown upon this subject by making infusions or macer- left beneath a bell-jar at the end of the mantelpiece in my ations from cut fragments of various plants, and then ex- study; while the other (a very small portion), which we amining, at different periods, the scum or pellicle that may name B, was put into a small half-ounce earthenware forms on such fluids. What I have now to say will refer pot, over which the cover was placed. The two specimens almost exclusively to infusions made from hay. The hay of the infusion, covered and uncovered, were then left side employed may be either fresh or old, but it does not do to by side beneath the bell-jar, so that the temperature to substitute for hay mere unripe grasses. I have elsewhere which they were exposed might be as nearly as possible shown how remarkably different are the products derivable similar. Some of the changes in the scums that formed on from living unripe grasses and from ordinary hay.'

the surface of these fluids are now to be described. In making such an infusion I have been accustomed to cut the hay into short pieces, to place these in a little beaker,

Origin of Flagellate Monads from Minute Masses of and then to add water so as well to cover the fragments.

Zoo gloea. After maceration for three or four hours at a temperature

A. When examined fifty-one hours after the time of f about 86° F. (30° C.), the infusion has been filtered filtration the scum on this infusion was found to be very through two or three layers of the finest Swedish filtering thickly crowded with small masses of Zooglæa varying paper into another small beaker. In this way all but the much in shape and actual size, as shown in Fig. 1, A. smallest particles, 1/12,000 of an inch or thereabout, will be excluded. For observation of the changes now to be described it is best that the bacterial scum, which soon forms on the surface of the fluid, should be very thin, therefore the depth of the fluid ought not to be more than about one and a half inches—though if one is seeking to make out the origin of ciliated Infusoria infusions of greater depth should be employed in order that a fairly thick pellicle may form.

When such an infusion is kept under a bell-jar (to exclude dust) at a temperature of about 65° F. (18° C.), the pale sherry-coloured fluid in less than twenty-four hours becomes lighter in colour and very turbid. Soon a scum, almost invisible, begins to form on the surface, composed of several different kinds of bacteria, and in about thirty-six hours small Zooglæa masses of the most varied sizes and shapes hegin to appear therein. In Fig. 1, A, a portion of such a sum is shown as it appeared at the end of the third day on a hay insusion in which the masses of Zooglaa were Peceptionally numerous. The portion of this scum here represented had been transferred on the tip of a sterilised S. alpel to a drop of a dilute solution of eosin, which stained the surrounding bacteria a pale red tint, but left the Zooglæa masses unstained, so that they were rendered very distinct. Had logwood been used the results would have been reversed—that is, the Zooglæa areas would have been

FIG. 1.-A, Zooglæa masses in the scum on a hay infusion (X 100); B more or less deeply stained, while the surrounding bacteria A portion of one of these masses showing the contained bacteria (x 500). would have remained unstained.

Examination of one of these masses with a high power In the course of the fourth day very many of the smallest will show its constitution, and reveal the fact that we have

masses were seen to be undergoing segmentation into small to do with an aggregation of separate bacteria imbedded motionless spherical bodies, while multitudes of active in a jelly-like material. This may be seen from Fig. 1, B, flagellate Monads of the same size were for the first time which shows a highly magnified portion of one of the seen in the fluid and in the midst of the portion of the scum Zooglaa masses from the same pellicle after it had been under examination. When a similar examination had been immersed in a drop of a weak solution of Ehrlich's eosino- made twelve hours previously not a single Monad was seen ; phyle fluid, which stained the surrounding bacteria a now there were swarms of them, and all were of about the yellow tint, while it left the Zooglæa mass unstained. The same size. slightly altered bacteria within the Zooglæa mass are at In Fig. 2, A (x 500), some of these small masses are this early stage plainly to be seen, though later on they shown together with their contained bacteria ; B (* 375) become more or less obscured by reason of progressive shows a number of the small masses undergoing segmentmolecular changes taking place in the mass during its ation ; while C (x700) shows one of these bodies more subsequent transformation.

highly magnified, in which the segmentation into embryo Some of these Zooglæa masses are destined ultimately Monads, still in a motionless condition, is almost complete. to be converted into numbers of flagellate Monads or of

In the course of the next day the Monads were found Imæber, while others become resolved into heaps of Fungus

in prodigious numbers. They were spherical or ovoidal in germs. I have found it impossible to tell from the mere

shape, and provided with a single flagellum about twice microscopical appearance of the Zooglæa masses whether the length of the body. C'nder a high power a nucleus they are destined ultimately to yield Monads or Fungus- could be distinctly seen, generally surrounded by a circle germs. The latter transformation is undoubtedly by far of very minute granules. In addition, two or three larger the commoner of the two, and when I was working for

granules were to be seen-one of them, larger and more many months at this subject during 1899 I was unable to

highly refractive than the others, being often present in the 1 Studies in Heterogenesis," p. 87 (1904).

1 “Studies in Heterogenesis," pp. 69-73, Figs. 53 55.

[graphic]

posterior half of the body of the organism, and there showing faint oscillations. Numbers of the Monads that were aggregated between three small contiguous air bubbles are shown in Fig. 2, D (X125), as they appeared under a low power of the microscope. Many of them were in active

B. The closed pot was not opened until the end of the fifth day, and I then found the surface of the infusion covered with a very thin, scarcely perceptible film of bacteria, which on microscopical examination was seen to be densely crowded with very minute Zooglæa masses such as are shown in Fig. 3, A (x 500). Not a single Monad was to be seen, but many of the masses were found to be about to segment as in B, or actually segme ing as in C into a number of motionless spherical corpuscles.

During six subsequent days I uncovered the pot for a moment to take up on the tip of a sterilised scalpel a portion of the scum for examination, and on each occasion found the minute Zooglæa masses presenting similar characters, except that day by day a rather larger number of them showed evidences of segmentation, though not a single active Monad was to be seen.

The Zooglæa masses formed in the dark, and in a comparatively airless pot, were not only different in character from those formed in the open vessel, but it would seem that their process of change was slower and was in part arrested by the opening of the pot, since after eleven days there was still not a single active Monad to be seen, though in the open vessel swarms of them were found during the fourth day.' This arrest of the process of change recalls the similar arrest which was always found to occur when the pot was opened in which Hydatina eggs were being transformed into ciliated Infusoria of the genus Otostoma.

It so happened that on the very day that I first observed the segmentation of the small Zooglæa masses in A I had

[graphic]
[graphic]

Fig. 2.-A. Small Zooglæa masses from the hay infusion (X 500); B, Other

of these masses undergoing segmentation (X575); C, One such mass the segmentation of which is nearly complete (x700); D, Monads derived from products of segmentation (X 125).

movement and are not shown, but those that were stationary were photographed by a very brief exposure. I found it impossible to photograph these particular Monads under a high power because they were mixed up with active bacteria, and were themselves very delicate in texture. The movements of these bacteria could not be arrested except by a

[graphic]

Fig. 4.-A, Minute Zooglæa masses in various stages of change (X 500);

B One of these masses in which segmentation has been nearly com

pleted (x700). B

on my work-table under a bell-jar a small petri dish in which a tuft of dead lichen had been soaking for a few days in distilled water. There was a very thin scum here and there on the surface of this water, and on examining a portion of it I was surprised to find that it also was crowded with small Zooglea masses, many of which were apparently in different stages of segmentation into Monads, though the majority of them showed no signs of segmentation. Being busy with what seemed at the time to be the more important A infusion, I did not examine this new scum again until after the expiration of two days, and then I found crowds of active Monads, and all the Zooglea masses now in different stages of segmentation such as are shown in Fig. 4, A (500). The only portion of an unaltered mass that I could find is seen on the left hand side of this figure, contiguous to the black speck. In the two days all the small Zooglæa masses had either

1 Examinations of the scum taken from the pot have since been made at FIG. 3.-A, Portion of pellicle taken from the pol (* 500); B, Small Zooglen

intervals during another week, and still, up to the eighteenth day, not a masses about to seginent (500); C, Small Zooglæa masses which have

single Monad has been met with, though very many of the small Zooglaa undergone complete segmentation (x 500).

masses have been found segmenting into pale brown Fungus-germs. But nine days ago (in order to test the question whether th- premature opening

of the pot bad caused an arrest of the formation of Monads) I made another comparatively strong osmic acid solution, or by exposure similar infusion from the same hay, and placed some of it in another small to the vapour of a i per cent. solution for more than half hall-ounce pot, which was opened for the first time to-day. In the first a minute, and in either case the result was to make the portion of the scum obtained from this second pot I found swarms of active Monads almost invisible, if it did not cause their complete segmentation of other of the Zooglea masses. - November 14.

Monads, and also heaps of the small brown Fungus-germs resulting from the diffluence.

“Studies in Heterogenesis," pp. 49-51, and xiv.

[merged small][merged small][graphic][subsumed][graphic][merged small]

F66. 5-A, Products of segmentation stained, and appearing as minute

been unable to ascertain, though I know that in rare cases spherical nucleated cells (x900); B, Monads in a resting stage (x700). swarms of minute Amæbæ rather than Monads appear in

this way in hay infusions. The production of swarms of shown in Fig. 5, A (x900), after they had been lightly minute Amabæ is, however, the rule in the pellicle that stained with Westphall's mastzellen Auid. In this forms on an emulsion made by pouring about eight ounces embryonic condition the future Monads are seen as spherical of water on a teaspoonful of mixed white and yolk of egg. nucleated cells, either single or in pairs. Some of the Such Amabæ, slightly stained with logwood, are shown in

Fig. 6, B (x 200), taken from a pellicle on the seventeenth day, while in C (x 125) they are seen, as I believe, originating in another egg and water emulsion on the eighteenth day, in the midst of irregular clumps of bacteria. These aggregates of bacteria had been noticed for several days, but when first observed not a single Ameba had, up to this time, been seen either in them or in the surrounding

[graphic]
[graphic][merged small]

fluid. Then there were appearances as though changes

were taking place within the aggregates, followed in two Pic 6.-A, Monads developed from Zooglæa masses in a hay infusion or three days by the presence of swarms of minute sluggish

( * soo): B, Amabæ stained with log wood, from an egg and water emulsion (200); C, Amcebæ originating in the scum from an egg and

Amæbæ around, and issuing from, the bacterial aggregates, water emulsion (X 125).

as shown in the figure under a low magnification.

In reference to the occurrence of these swarms of minute Monads which were found a few days later in a motionless, Amæbæ, I may say that I have never seen one of them resting condition, are shown in B (x700).

multiply by fission, and certainly their vast numbers are On other occasions I had been a little more successful not to be accounted for in this way. I make these remarks in photographing Monads produced from Zooglæa areas in concerning Amæbæ without pretending that what I have a hay infusion. Thus Fig. 6, A (X 500), shows some such here said in regard to them is quite conclusive, or in any

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