NATURE 



25 



THURSDAY, NOVEMBER 10, 1892. 



EXPERIMENTAL BIOLOGY. 



Experimental Evolution. By Henry de Varigny, D.Sc, 

 (London : Macmillan, 1892.) 



DR. HENRY DE VARIGNY has enriched the 

 literature of biology by publishing in the " Nature 

 Series " the lectures on " Experimental Evolution " de- 

 livered by him in 1891 to the Summer School of Art and 

 Science in Edinburgh. This school, as is well known, 

 lias been ^oing good work on Extension lines in Edin- 

 burgh, and Prof. Geddes is to be congratulated on having 

 secured the co-operation of so able a biologist and so 

 lucid an exponent of the special aspects of biology with 

 which he has identified himself as M. de Varigny. The 

 lectures are well worthy of publication, for they contain 

 a rich, well-ordered, and, for the most part, well-sifted 

 body of facts collected from many sources, and especially 

 from the publications of French naturalists. But the 

 author is more than a collector of facts recorded by other 

 workers ; he is himself a worker in this special field of 

 biological science. And some of the most valuable of 

 the observations contained in the work are the result of 

 Ills own careful and exact investigations. 



Experimental biology is still in its infancy. It is true 

 that our domesticated animals and plants are the result of 

 much experimental work in the past ; but the experiments 

 were not planned with the object of explaining organic 

 nature, and were therefore not biological in their aim. 

 There is pressing need at the present time for experi- 

 ments with such definite scientific aim ; for experiments, 

 that is to say, carried out with the express object of 

 testing the truth of biological principles. And that this 

 work be well done there is pressing need for organization. 

 We have only to look at the results which have been 

 reached by well-planned and well-directed marine 

 stations in extending our biological knowledge, faunal, 

 morphological, and embryological, to see what may be 

 done by organization of research. What Dr. de Varigny 

 eloquently pleads for, and what our own countryman. 

 Dr. Romanes, is also pleading for, is an experimental 

 institute, well planned and adequately supported, the 

 purpose of which shall be to carry out extensive experi- 

 ments for testing evolution hypotheses in all their 

 bearings. 



"It appears to me," says Dr. de Varigny, "that this 

 institution should comprise the following essential ele- 

 ments : — Rather extensive grounds, a farm with men 

 experienced in breeding, agriculture, and horticulture ; 

 some greenhouses, and a laboratory with the common 

 appliances of chemistry, physiology, and histology. Of 

 course this must be located in the country. It is very 

 important to have experienced farm hands, and a good 

 chemist and histologist are necessary in the staff of the 

 institution. As to the general management, it seems 

 advisable to have a director with a board of competent 

 men, whose functions would be to decide, after careful 

 investigation and exchange of views, what are the funda- 

 mental experiments to be performed. These experi- 

 ments, when once decided upon, should be pursued 

 NO. I 202, VOL. 47] 



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 use- 

 less, 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 obser- 

 vations are confirmatory of those of Mr. Mann Jones. 

 Mr. Hudson, in a very interesting chapter of the " Natural- 

 ist in La Plata," gives observations which tend to show 

 that young birds afford little evidence of instinctive 

 fear of particular enemies ; and my own experi- 

 ments 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.^:, 

 a chord on the violin), any large approaching object (e.^., 

 a ball rolled towards them), causes alarm. There is no 

 evidence of instinctive particularization of alarming ob- 

 jects. 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 modem 

 evolution, that of natural selection, stands in no need of 

 experimental verification. But it will presumably be ad- 

 mitted, 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 in- 

 exorable 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 pro- 

 creation : 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 



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