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conceive the latter as a separate branch of of this work, and the recent researches of physics aod mechanics. But we shall | Strasburger, Flemming, Guignard, and postpone the analysis of these endeavors, Fol, while fully confirming the broad gen. hoping that some opportunity may soon eralizations laid at the foundation of modbe offered to come to some more definite ern biology, revealed a wide series of new ideas out of the conflicting theories of the facts having a direct bearing upon the present moment.
question of heredity, which is so much
debated now in connection with WeissIV.
mann's views.* WHEN Schwann, closely following upon It appeared, first, from the above-menRobert Brown's and Schleiden's work, tioned researches, that protoplasm itself published in 1839 his famous “Micro- consists of, at least, two different subscopical Researches," and came to the stances; one of them being a minute netconclusion that all possible tissues of both work of very delicate fibrils, while the animals and plants consist of cells, or of other is an apparently homogeneous submaterials derived from cells, it seemed stance filling up the interstices between that the primary units - the molecules, so the network. Then it became evident to say — of which all living beings are that the nucleus which makes a necessary built up, had finally been discovered. A constituent part of cells, has a still more small piece of structureless, granulated, complicated structure, and that it plays a jelly-like substance - the sarcode in ani- most prominent part in all the phenomena mals and the protoplasm in plants - suro of subdivision of the cells and those of rounded or not by a thin membrane, and reproduction. It consists of a nuclear containing a nucleus, this was the pri- plasm, surrounded by a very thin memmary unit, giving origin to all the most brane; it contains very often a still complex and varied tissues.
smaller nucleolus ; and within the nuclear This conception evidently gave a for- plasm the microscope discovers extremely midable impulse to science and to scientific thin threads, or fibres, consisting in their philosophy altogether, the more so as it turn of extremely thin minute granules, or was soon followed by a most important spherules — the whole appearing as a ball discovery which established the close re- of thread coiled up somewhat roughly.t semblance existing between the subdivi: This being the usual aspect of the nucleus, sion of cells and the phenomena of sexual a series of modifications begin within it, reproduction in plants and animals. Twen- when the moment comes for a cell to sub. ty-two years later, another still more divide. The nucleolus disappears; the important step was made in the same beaded threads, or fibres, shorten and bedirection, when Max Schultz published come thicker. They take the shape of his memoir, “Das Protoplasm,” and minute hooks, and these hooks join toproved that the granular, jelly-like sub- gether (by the tops of the bendings) in one stance of the cells is identical in both the point, the pole. By the same time the animal and vegetable kingdoms; that it is membrane of the nucleus is reabsorbed, the very seat of all physiological activity, and the surrounding protoplasm of the as it is capable of movement, of nutrition, cell penetrates within the nucleus, thus of growth, of reproduction, and even of mixing up together with the nuclear plasm. sensibility, or, at least, of irritability. Thereupon a most important change fol. Many must certainly remember the effect produced by the broad generalizations • Strasburger, Ueber Kern und Zell Theilung im based upon Max Schultz's ideas by botanique de France, 1890, t. 36, and Comptes Rendus,
Pflanzenreiche, Jena, 1888; Guignard, in Bull. Soc. Haeckel in Germany and Mr. Huxley in 1891, t. 112, pp. 539, 1074, and 1320; 1. 113. p. 9171 this country, in his well-known lay sermon, 1891, Bd. 37, p. 249, and Anatomischer Anzeiger, “ The Physical Basis of Life.”
However, if protoplasm were the seat up upon this subject. Excellent résumés of the whole of physiological activity; if it could move, Prof. McKendrick in Proceed. Glasgow Philos. Soc., grow, reproduce itself, and display irrita- vol. xix. ; and to the end of 1890 by Sir William Turner, bility, was it still to be considered as a in an address, "The Cell Theory, Past and Present,' "structureless, granulated jelly or slime”? scopical Society (Nature, vol. xliii., p. 11 and sq;) It was a world in itself, and the micro- + The albaminous matter of which these threads conscope had to be directed towards the fur- sist received the name of “nuclein," and the threads
themselves were named “chromatin fibres," owing to ther study of this world. So it was, by their affinity to coloring matter. The transformations Lionel Beale, Schultze himself, Stras in the nucleus which have just been described received lows. Each of the thickened nuclein | is now formed by both coalesced nuclei, fibres, or threads, splits in its length, and surrounded by a radiation of the fibrils of the number of the threads being thus protoplasm. Then begins what Fol pames doubled, one-half of them is attracted the quadrille of the centres." Each of towards a radiated spindle-figure in one them divides into two half.centres, and all part of the cell, while the other half ar- four move, so that each half-centre of the ranges in the same way in its opposite male cell meets and coalesces with one part. The two radiated figures thus sep-half-centre of the female cell, and the two arate, and only then (if the nucleus sub- newly formed centres become the poles of divides in giving origin to two new cells) a attraction for the spindles of the nucleus. membrane, or parts of a membrane, grow The act of fecundation is thus not a simple between the iwo. After the separation, coalescence of two nuclei, originated from the fibres either coalesce with their ends, two separate individuals, as was supposed or return in the shape of a ball of thread. before; it also consists of the union of
the general name of "karyokinesis," or “nuclear burger, and most histologists of renown. movement." The names, as seen, are simply descrip Discovery upon discovery was the reward tive.
It is a whole world undergoing a whole each two of the four half-centres originated cycle of modifications. And yet this is not in the protoplasm. all. It appears from Strasburger's work The interest attached to these minute that all the cells are not quite similar, but changes is great, on account of their conthat the number of nuclein fibres varies sequences as regards the theory of heredfrom eight to twelve and to sixteen inity. The observations of Fol, and the various families of plants, the individuality quite analogous observations of Guignard of the types thus seemingly depending as regards plants, would only confirm the upon their number; while Guignard found doubts expressed by Sir William Turner that with several plants the cells which in his address before the Microscopical will be destined, after the division of the Society,* as to the germ plasm being "so mother cell, to become the reproductive isolated from the cells of the body generorgans will always have but one-half of ally as to be uninfluenced by them, and to the normal number of fibres (say twelve), be unaffected by its surroundings;" and while those which are destined to become they would give further weight to its rethe vegetative organs will have the full strictions as regards Weissmann's theory number-say, twenty-four.* The former of heredity. However, the questions at will acquire the full number of fibres only issue are so complicated and so delicate, after fecundation. Are, then, the cells that further research is wanted, and eagerly differentiated from the first moment of expected by specialists. their bi-partition? And what part does But what is protoplasm itself? What is the number of chromatin fibres play in this jelly-like matter which exhibits all that differentiation ?
phenomena of life? Science has not yet Further complications are discovered given a positive answer to this great questhrough the study of the protoplasm itself. tion. On the one side, we have the germs It was known some time ago that there of an opinion, shared by some biologists are, in the animal cells, two peculiar spots, who are inclined to see in protoplasm an surrounded by rays of sarcode, which were aggregation of lower organisms. Thus named spheres of attraction, or directing R. Altmann † and I. Straus & consider that spheres, or centrosomata, or simply "cen- the granulations of protoplasm are the tres." The same minute centres have essential and fundamental elements of the now been found by Strasburger and Gui-organic being. As to the cell, it is not, in gnard in vegetable cells also, and it ap- Altmann's view, an elementary organism, pears that these bodies, essentially belong- but a colony of elementary organisms which ing to the protoplasm — not to the nucleus group together according to certain rules
- take a leading part in the phenomena of of colonization. They constitute the proreproduction. Professor Fol, who carried toplasm as well as the nuclear plasm, and on his researches with eggs of sea-urchins, they are the morphological units of all saw that when the elements of the male living matter. These graoules, he maincell have entered the female cell, the cen- taios, are identical with microbes; their tre of the former separates from the top shape, their chemical reactions, their of its nucleus and joins the centre of the movements, and their secretory functions latter. Both lie close to one another; then are similar; but the granules of the prothey become elongated and take positions on the opposite sides of the nucleus, which • See first note, p. 11.
† Die Elementar-Organismen und ihre Beziehungen Report upon which the Prix Bordin was awarded zu den Zellen, Leipzig, 1890, with twenty-one plates. to Guignard, in Comptes Rendus, December 21, 1891, Fournal de Micrographie, t. 15, October 25 1891.
# "Sur la morphologie de la cellule bactérienne," in p. 917.
toplasm differ from bacteria in not being origin.* The compound eye coasists, as capable of a separate existence. They known, of hundreds and thousands of can only live in cells. It is absolutely separate conical, almost cylindrical, parts, impossible to say, at the present time, each of which corresponds to a separate how far this view may find support in eye; however, their structure widely difulterior research, though it must be men- fers from that of the mammalian eye. tioned that it is derived from elaborate Each of the component eyes has, like ours, investigations into the cells of various a cornua, but it is flat, and the crystalline glands and their secretions, and that it part of the eye has not the shape of a fiods support in facts accumulated by lens, but of a “leos cylinder," that is, of a many well-known anatomists.* It must cylinder which is composed of sheets of also be added that some biologists — transparent tissue, the refracting powers namely, J. C. Vogtt-go a step further of which decrease towards the periphery and maintain that all micro-organisms, and of the cylinder. If an eye of this kind is all cells of more complicated organisms, removed and freed of the pigment which are structures of a fourth or higher order; surrounds it, objects may be looked at they are colonies of “polyplasts,” which through it from behind; but its field of themselves consist of " monoplasts,” or vision is very small, and the direct images those granules which are distinguished in received from each separate eye are either the protoplasm and the nuclear plasm. produced close to one another on the But, on the other side, we also have the retina (or rather the retinulæ of all the other extreme view, supported by the eyes) or superposed. In this last case no authority of Professor o. Bütschli, who less than thirty separate images may be sees in protoplasm nothing but a foam, superposed, which is evidently a great quite similar to the foams which may be advantage for nocturnal insects. Many artificially produced, and who maintains other advantages are derived from the that all phenomena observed in living pro- compound structure of the insect eye. toplasm are simply physical and chemical Thus the mobile pigment which corre. processes.
sponds to our iris can take different posi. The great question as to what proto- tions, either between the separate eyes or plasm is, evidently will not be solved soon. behind the lens cylinders, in which case But the above-mentioned researches will it acts as so many screens to intercept the give an idea of the problems which at this over-abundance of light. Moreover, it moment absorb the attention of biologists. has been ascertained by Exner that with One important step has certainly been its compound eye the common glow-worm made : the complicated structure of pro- (Lampyris) is capable of distinguishing toplasm has been recognized, and the large sign-board letters at a distance of exploration of the vital processes in "liv- ten or more feet, as also extremely fine ing matter” now stands on a firm footing.I lines engraved 'or of an inch apart, if they
are at a distance of less than half an inch
from the eye. As a rule, the compound It is known that Darwin, when he be eye is inferior to the mammalian eye for gan thinking about the possible origin of making out the forms of objects, but is the eye, used to feel a kind of shudder in superior to it for distinguishing the small. consequence of the difficulties standing in est movements of objects in the total field
An important step towards of vision. smoothing these difficulties has now been All stages of evolution of the eye may made by Professor S. Exner, who has be studied among the insects and the brought out an elaborate and richly illus. Arachnides. Thus, beginning with the trated work on the eyes of crustaceans and eye of the Limulus, Mr. Watase shows insects, § and by Mr. Watase, who has how it may have originated from a simple studied the question as to their possible minute cavity in the epithelium. The
sensitive cells lie in direct continuity with The author dames Gianuzzi, Ranvier, Renaut, those of the epithelium, or hypodermis; and partly Henri Martin.
and a cavity, with a pigment cell therein, Das Empfindungsprinzip und das Protoplasma, auf Grund eines einheitlichen Substanzbegriffes, Leip- and covered by epithelium, may represent nig, 1891; Fournal of the Microscopical Society, the first rudiment of the eye. Later on February, 1892.
Prof. R. Greef's exploration of the motor-fibrils of the cavity deepens, and the roughly conthe Amæba terricola (Biologisches Centralblatt, November, 1891, pp. 599 and 633) may be mentioned as • "On the Morphology of the Compound Eye of an illustration of such researches.
the Anthropodes," in Studies from the Biological 9 Die Physiologie der facettii ten Augen von Kreb- Laboratory, Johns Hopkins University," vol. iv. (Balo sen und Insecten, Leipzig, 1895.
ical thickening of the epidermis which exhausted, while the dark lines under her fills it becomes the "lens cylinder." eyes told a story of study protracted late
A succession of drawings made by Mr. into the night. She was dressed in some Watase upon the simplest forms of the kind of loose-fitting gown, of a style free ocellæ of larvæ and some millepeds per- and unfashionable; her dark-brown hair fectly well illustrate the various possible was cut short, in the way that many girls phases of evolution of the eye, from the now choose for comfort and convenience ; minute cavities, or ocellæ, which appear not any of her features were beautiful, but in great numbers, closely packed together, there was the beauty of thoughtfulness to the more complicated eyes described about her face. Her table was strewn by Exner. We thus have in Mr. Watase's with exercise and lesson books, and a few work, confirmed by another work, by M. set apart were obviously for her own priKishinouye,* a most valuable contribution vate work, being several volumes of biolto the solution of one of the complicated ogy, inorganic chemistry, and physics, and problems of the doctrine of evolution. Salmon's “ Conic Sections," and Smith's
We can only mention several very in. " Analytical Conics," and two or three teresting works on the origin of the frowning treatises on trigonometry. Her prickles in various plants, on the effects little sitting room, rather comfortless in its of high altitudes upon animals, on the poverty, had for ornaments two or three compound structure of the higher plants photographs of pictures from the National and the effects of atavism, and so on - Gallery, and a photograph of Watts's all resulting from the modern endeavors beautiful picture of “Hope." This picof many biologists at explaining the origin ture faced Gertrude Hurst's writing-table, and development of variations in animals so that every time she raised her eyes and plants under the effects of their sur. from her work, they fell naturally there. roundings. A good deal of attention be. The other ornaments of the room were a ing paid now to the chapter of " direct few books, held together by a home-made adaptation "in the theory of the evolution book-shelf. On the fire the kettle was of species, many interesting facts are con boiling merrily, waiting impatiently until tinually brought to light by the work of it should please the lady to fill the little the modern followers of Lamarck. black teapot which was reposing in a cor
P. KROPOTKIN. ner of the fender. A shabby white cat
was sitting upright on the hearth, con• Zoologischer Anzeiger, 1891, vol. xiv., p. 381 ; templating with learned gravity some Journal of the Microscopical Society, February, 1892, loose sheets, which had fallen to the p. 38.
ground, and which were covered with fig. ures and signs having something to do with parabolæ and tangents, asymptotes
and other mathematical mysteries. The From Blackwood's Magazine.
room was evidently that of a solitary stuTHE MATHEMATICAL MASTER'S LOVE
dent, and yet the slight figure of the girl STORY: A RECORD.
yonder seemed so childlike, that at first sight she might well have been taken for
a child; only on closer inspection one It was about half past five, on a March could see that she had lived through years afternoon some few years ago, when Ger- of toil and of sorrow, and had learned trude Hurst, worn out with a long morning things which time alone can teach. of teaching, and a long afternoon of cor. Gertrude Hurst must have been sleeprecting books, let her pen slip from hering for more than half an hour, when some hand, and leaned back in her armchair, one knocked at the door. Receiving no just for a few moment's laziness. “I will answer, the person asking for admittance not even shut my eyes,” she said, as refused to be kept waiting any longer, and though in excuse to herself for this un- opened the door for himself and looked wonted indulgence.
into the room. Then, seeing the sleeper But Nature inexorably claims her own, in the armchair, he stood hesitating what and before many minutes had passed, this to do. tired London high-school teacher had “Poor tired child !” he whispered; "she fallen fast asleep. Her arms rested list. is woru out with work.” lessly on each side of the chair, and her He went gently up to her side and bent head was pressed against its cane back. over her, and stooping down, picked up There was a worried look on her thin face; the pen which had fallea from her hand, and indeed her whole strength seemed and replaced it on the inkstaud. He lin
gered by the fireplace as though he were before his time, but the enemy, consump. reluctant to go away;
tion, had not been able to rob him of "I suppose I ought to go," he said to everything, and there was still a pleasing himself; “for she thinks I am still in sort of defiance in the way in which he Australia, and I should startle her on her carried his head — a head which had not first awakening."
submitted itself to the doubtful mercies And agaio he murmured to himself: of the conventional barber. His eyes “ Poor child! she is worn out. I am glad seemed fixed on distant objects, as though I have come home to belp her.”
they were tryiog to penetrate into that loPerhaps he would have really gone; but finite which is the pleasure-ground of all at that moment the black kettle boiled mathematicians. For a mind bent on tanover, and Elkin Anderley bent down to gents and parabolæ and hyperbolæ, on rescue it from the indignant fire, whilst sines and cosines, and the resultant of the shabby cat looked calmly on, as though forces, and the properties of cones, is it uoderstood all about the proceedings, allowed on all hands to be hopeless, so far and did not intend to rufile itself on ac- as the plain and matter-of-fact things of count of an agitated kettle. The kettle the outer world are concerned. And was placed in safety on the hob; and Elkin Aonerley, the young mathematical Elkin Anderley was just turning towards master, whose bad health had obliged him the door, when he suddenly caught sight to give up all his work and his prospects, of those papers lying under the armchair. seemed quite to have lost himself, as he And a few well-known hieroglyphics ar- sat there working out problems, probably rested his attention, everything that was suggested by these others which he had mathematical in him arose in excitement. just been correcting. His hand moved He took up the loose sheet as though it over the paper quickly, and then as were some precious gem, and began to quickly crossed out all the working, the examine it; then he frowned and shook writer shaking his head in vexation. his head, and mechanically drawing a “ That was not the shortest way of pencil out of his pocket, he made some doing it,” he said. “Ah! this is far neater few corrections.
and prettier. It would be a good rider to “ The whole thing is wrong," he said set for an examination paper. I shall impatiently; "waste of time and waste of make a note of it." paper. She ought to be ashamed of her- Whilst he was thus busily engaged, self, after all my teaching, too."
Gertrude Hurst awoke, and, turning He spatched from the shelf a large book round, saw her visitor. She rose, and on which to fix the paper, and he settled stood waiting until he should look up. At himself in a low chair near the fire, and last he did look up, and she said: “Why, rested his feet against the fender. He I thought you were in Australia, Mr. Anwas soon lost in the interesting and ab. Derley. I have been wondering all the sorbing nature of his work; and to judge time how you were gettiog on there." from the far-away look on his face, be That was all she said, but there was a bad probably forgotten everything save glad smile on her frank face, which told the one important fact that here was a how pleased she was to welcome him most intricate problem badly worked out, back from Australia. He had thrown aside in defiaoce, too, of some of the most ele- his papers, and stood beside her. mentary mathematical rules and formulæ. “Do you know," he said, “you look
“This is just the sort of carelessness very tired ? And you cannot disguise to irritate me," he said. “Perhaps it is a from me that you have fallen asleep over good thing for my pupils that I am not your work." now teaching mathematics."
She pushed the hair off her face, and His face cleared, though, when he laughed. “Is that all you have to say, turned over the page and found some after your long voyage to Australia ? " she other problems cleverly worked out. said. " I should have thought you would
“Come, come,” he said, “ this problem have had some remarks to make about the redeems the other.” And with the old climate, or your fellow-passengers, or the instinct of a master, he put V. G, at the steamer.' end of it, and signed his initials E. A., “That may come later," he answered, smiling somewhat mournfully as he did so. as he watched her busying herself about
He was a man of about thirty years of making the tea. age, very frail, and of medium height. “Perhaps you'll clear the table ?" she He had the appearance of being worn out said to him, " and get the cups and sau.