THURSDAY, NOVEMBER 10, 1892.

EXPERIMENTAL BIOLOGY. Experimental Evolution. By Henry de Varigny, D.Sc. (London: Macmillan, 1892.)

DR.

R. HENRY DE VARIGNY has enriched the literature of biology by publishing in the "Nature eries" the lectures on 66 Experimental Evolution" devered by him in 1891 to the Summer School of Art and cience in Edinburgh. This school, as is well known, as been doing good work on Extension lines in Edinurgh, and Prof. Geddes is to be congratulated on having ecured the co-operation of so able a biologist and so acid an exponent of the special aspects of biology with hich he has identified himself as M. de Varigny. The ctures are well worthy of publication, for they contain rich, well-ordered, and, for the most part, well-sifted ody of facts collected from many sources, and especially rom the publications of French naturalists. But the thor is more than a collector of facts recorded by other orkers; he is himself a worker in this special field of iological science. And some of the most valuable of e observations contained in the work are the result of s own careful and exact investigations. Experimental biology is still in its infancy. It is true at our domesticated animals and plants are the result of uch experimental work in the past; but the experiments ere not planned with the object of explaining organic iture, and were therefore not biological in their aim. here is pressing need at the present time for experients with such definite scientific aim; for experiments, at is to say, carried out with the express object of sting the truth of biological principles. And that this ork be well done there is pressing need for organization. 'e have only to look at the results which have been ached by well-planned and well-directed marine ations in extending our biological knowledge, faunal, orphological, and embryological, to see what may be ›ne by organization of research. What Dr. de Varigny oquently pleads for, and what our own countryman, r. Romanes, is also pleading for, is an experimental stitute, well planned and adequately supported, the rpose of which shall be to carry out extensive experients for testing evolution hypotheses in all their arings.

"It appears to me," says Dr. de Varigny, "that this stitution should comprise the following essential eleents :-Rather extensive grounds, a farm with men perienced in breeding, agriculture, and horticulture; ne greenhouses, and a laboratory with the common pliances of chemistry, physiology, and histology. Of urse this must be located in the country. It is very portant to have experienced farm hands, and a good emist and histologist are necessary in the staff of the titution. As to the general management, it seems visable to have a director with a board of competent n, whose functions would be to decide, after careful estigation and exchange of views, what are the fundantal experiments to be performed. These experints, when once decided upon, should be pursued

during a long period of years, and nothing should be altered in their execution unless considered advisable by the board, or unless the experiment should be found useless, or devoid of chance of success. The main thing should be to provide for the duration of the experiment, whether the originators were living or dead, and to follow it out for a long time. Time is an indispensable element in such investigations, and experiments of this sort will surely exceed the normal duration of human lifetime.”

A special branch of the work of such an institute should be experimental investigations in comparative psychology. Of this there is nowadays some need. Speaking of the transmission of acquired characters, Dr. de Varigny says, "Psychology affords similar instances. A kitten which has never seen a dog is afraid from the first moment it perceives one; young birds of many species instinctively fear the hawk and other birds of prey, while remaining unaffected by the presence of other birds. Are not these psychological 'attitudes' due to environment (acting on the mens of ancestors) which have been transmitted by inheritance; are these not acquired characters ?" From observations of my own I am prepared to say that it is by no means universally true that a kitten which has never seen a dog is afraid from the first moment it perceives one. Mr. Spalding does indeed describe how the smell of his hand with which he had been fondling a dog set four blind kittens puffing and spitting in a most comical fashion. But a careful observer, Mr. Mann Jones, writes to me that a young kitten with which he experimented "took eight days to connect the smell or odour of his hand with the thing-dog." And my own observations are confirmatory of those of Mr. Mann Jones. Mr. Hudson, in a very interesting chapter of the "Naturalist in La Plata," gives observations which tend to show that young birds afford little evidence of instinctive fear of particular enemies; and my own experiments with young chicks lead me to believe that they have no instinctive knowledge of the things of this world. Any unusual and sharp sound (e.g., a chord on the violin), any large approaching object (e.g., a ball rolled towards them), causes alarm. There is no evidence of instinctive particularization of alarming objects. Such observations lead me to look with suspicion on any arguments for the transmission of acquired characters based on supposed instinctive knowledge of things. And they show the need of further research in comparative psychology such as could be carried out at the Institute of Experimental Biology.

It may be said that the central hypothesis of modern evolution, that of natural selection, stands in no need of experimental verification. But it will presumably be admitted, even by those who are firm in their belief, among whom I count myself, that further experimental support will be of the utmost value. There are many who assume a sceptical attitude, and who say-We grant the inexorable logic of your conclusions if your premisses be established. More individuals are born than can or do survive; the devil devours the hindmost; and a beneficent selection rewards the survivors with the privilege of procreation hence, progress towards increased adaptation. A very pretty piece of logic. But now, they say, show us the devil at work. We pretend to no particular knowledge

-Elements of the comet Barnard, of October 12, 1892, by M. L. Schulhof. On the algebraic integrals of the differential equation of the first order, by M. L. Autonne.-On centres of geodesic curvature, by M. Th. Caronnet.-On Pfaff s problem, by M. A. J. Stodolkievitz.-Sunspots and magnetic disturbances in 1892, by M. Ricco.-On considerations of homogeneity in physics; reply to M. Clavenad, by M. Vaschy.-Verification of parallelism of optic axes in uniaxial crystalline plates, by M. Bernard Brunhes.-On a photoptometric photometer, for the measurement of feeble illuminations, by M. Charles Henry. This is based upon the constancy of the phosphorescent sulphide of zinc. Its law of loss of brilliance being determined, it may be used for measuring very feeble illuminations, such as distant artificial light or the general luminosity of the sky due to the stars. The decrease of light after the first 900 seconds being given by 0.5 (t - 18.5) = const., it is easy to calculate the luminosity at any instant. In the instrument in question there are two screens of ground glass, one of which is illuminated by the phosphorescent sulphide, brought to its maximum glow at a certain time by burning magnesium ribbon, the other exposed to the source of light. It is then only necessary to wait till both the screens are equally illuminated, and to note the time. On the dissociation of chrome alum, by MM. H. Baubigny and E. Pechard.-On the temperatures of maximum density of aqueous solutions, by M. L. de Coppet.-On some double salts of quinine, by M. E. Grimaux. On the thermal value of the three functions of orthophosphoric acid, and on its constitution, by M. de Forcrand. -Preparation and properties of fibroine, by M. Leo Vignon.— Regeneration of the so-called sporangial form in the diatoms, by M. P. Miquel.-On the hematozoaria of cold-blooded vertebrates, by M. Alphonse Labbé.-Influence of coloured light on the development of animals, by M. E. Yung.-On the mode of fixation of the hexapod parasitic larvæ of the acarians, by M. S. Jourdain.—The cavern of Brassem pouy, by M. Edouard Piette. Discovery of a skeleton of Elephas meridionalis in the basaltic ashes of the volcano of Senèze, by M. Marcellin Boule. -Vegetable prints of the Dover boring, by M. R. Zeiller.

BERLIN.

Meteorological Society, October 11.-Prof. von Bezold, president, in the chair.-Dr. Berson reported on an interesting relationship which he had discovered between insolation and temperature. Since it has not yet been possible to determine accurately the absorption due to the atmosphere, the speaker had calculated the insolation at the external limit of the atmosphere, which admits of rigid mathematical treatment, both for the whole year and for the months of January and July. The mean of insolation for the whole year was found to lie at the thirtieth degrees of northerly and southerly latitude, so that the zone between these parallels, or about 60 per cent. of the whole external surface, receives more insolation than the mean, whereas the two polar caps, or the remaining 40 per cent., receive less. A similar calculation of the annual temperature gave the mean as at latitude 38° N. and 35° S., giving as before 60 per cent. of the surface with the temperature above the mean, and 40 per cent. below. In January 61 35 per cent. of the surface experienced an insolation above the mean and 60 per cent. a temperature above the mean, while in July the percentages were respectively 6137 and 61 33.-Dr. Zenker gave a short account of a research on the relationship between temperature and insolation on the earth's surface. He had accurately calculated the relationship both for regions comprising land only and water only, and arrived at some interesting conclusions as to the theoretical temperatures at various latitudes of continents and oceans.

Physical Society, October 21.-Prof. Kundt, president, in the chair.-Dr. Jäger gave an account of the measurements he had made, in conjunction with Dr. Kreischgauer, of the temperature-coefficient of electric conductivity of mercury. Dr. Arons demonstrated an arc-light between mercurial electrodes in vacuo. It yielded a dazzling white light, which was steady at the anode but flickered and jumped at the cathode: its intensity approximated to that of an ordinary carbon arclight. The heat given off by it was but slight so that the tube could be held in the hand; the temperature was highest at the cathode. Attempts were made to determine the resistance of the arc, but without result. It was found by the use of a telephone that the current is discontinuous. A spectroscopic investigation of the light revealed a lime-spectrum showing very

BOOKS and SERIALS RECEIVED.

Books.-The Great World's Farm: S. Gaye (Seeley).—The Zoological Record, 1891 (Gurney and Jackson).--Castorologia, or the History and Traditions of the Canadian Beaver: H. T. Martin (Stanford).—Transac tions of the Royal Society of Edinburgh, vol. xxxvi. Parts 2 and 3 (Edinburgh)-Les Alpes Françaises: A. Falsan (Paris, Baillière) -Calendar of the University College of Wales, Aberystwith. 1892-93 (Manchester, Cornish).-London Birds and other Sketches, revised edition: T. D. Pigott (Porter).-Contents and Index of the First Twenty Volumes of the Memoirs of the Geological Survey of India. 1859-83: W. The bald (Calcutta).— Memoirs of the Geological Survey of India; Index to the Genera and Species described in the Paleontologia Indica, up to the Year 1891: W. Theobald (Calcutta).-Star Atlas: Dr. H. J. Klein, translated. &c., by E. McClure, new edition (S. P.C.K.).-City and Guilds of London Institute Programme of Technological Examinations, 1892-93 (London).—Appareils d'Essai à froid et à chaud des Moteurs à Vapeur: M. Dudebout (Paris, Gauthier-Villars).-Canon Torpilles et Cuirasse: A Croneau (Paris, Gauthier-Villars).-Ostwald's Klassiker der Exakten Wissenschaften, Nos. 31 37 (Leipzig, Engelmann).-Gesammelte Abhandlungen über PflanzenPhysiologie. Erster Band: J. Sachs (Leipzig, Engelmann).-On the American Iron Trade and its Progress during Sixteen Years: Sir L. Bell (Ballantyne).-Universal Atlas, Part 20 (Cassell).

SERIALS.-The Physical Society of London, Proceedings, vol. xi. Part 4 (Taylor and Francis).-Botanical Gazette, October (Bloomington, Indiana). -Traité Encyclopédique de Photographie, Premier Supplément A. quat. fasc.: C. Fabre (Paris, Gauthier-Villars).-Zeitschrift für Wissenschaftliche Zoologie, liv. Band, 4 Heft (Williams and Norgate).-Morphologisches Jahrbuch, xix. Band, 1 Heft (Williams and Norgate).

On the Need of a New Geometrical Term-" Conju-
gate Angles."-Prof. A. M. Worthington
Printing Mathematics.-W. Cassie
"Sunshine."-Amy Johnson; C. V. B.

The Photography of an Image by Reflection.-Frede-
rick J. Smith

Induction and Deduction.-Edward T. Dixon

Bell's Idea of a New Anatomy of the Brain.-Jas. B.
Bailey.

Photographic Dry Plates.-Arthur E. Brown
The Genus Sphenophyllum. (With Diagram.) By
Prof. Wm. Crawford Williamson, F. R.S.
Dendritic Forms. By Sydney Lupton
Notes..

Our Astronomical Column:

Comet Brooks (August 28)

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