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THE POPULAR SCIENCE MONTHLY. 



changes ; changes in the constitution or sub- 

 stance he calls substantive variation, and these 

 various changes may be continuous or discon- 

 tinuous. The word homtzosis is substituted for 

 metamorphy this term being applied to cases 

 such as the eye of a crustacean developing 

 into an antenna, or the petal of a flower into 

 a stamen, etc. He has systematized the 

 sports, freaks, and redundancies of Nature, 

 and has done an amazing amount of hard 

 work in a field to which few have been hith- 

 erto attracted. He has also emphasized in 

 the most telling way one of the most impor- 

 tant factors in the doctrine of natural selec- 

 tion namely, variation. As to the author's 

 conception that the discontinuity of species 

 is at all sustained by this evidence, we can 

 not agree. His introductory pages and there 

 are many of them are as laborious reading 

 as similar portions of Buckle's History of 

 Civilization. Man's power of apprehension, 

 nowadays, has so far advanced that there is 

 no longer any necessity for iterating and reit- 

 erating self-evident propositions. 



Demonstrating, as he does, sudden and 

 spontaneous modifications in animals, he as- 

 sumes, without sufficient proof, that the di- 

 vergent characters of many species have 

 originated in this way. He asks, May not 

 specific differentiation have resulted from in- 

 dividual variation ? The answer to this would 

 be that if these extraordinary jumps are ever 

 perpetuated for a time even, like the double 

 operculum in Buccinum undatum, for exam- 

 ple, which he cites, the wildest species-maker 

 has never dreamed of making a separate 

 species of such freaks. They are hardly ac- 

 counted varieties. 



The author says that Lamarck's view 

 points out that living things can in some 

 measure adapt themselves, both structurally 

 and physiologically, to new circumstances, 

 and that in certain cases the adaptability is 

 present in a high degree. He also formu- 

 lates Darwin's theory as showing the survival 

 of those adapted to the environment. " Ac- 

 cording to both theories, specific diversity of 

 form is consequent upon diversity of environ- 

 ment, and diversity of environment is thus 

 the ultimate diversity of specific form. Here, 

 then, we meet the difficulty that diverse en- 

 vironments often shade into each other in- 

 sensibly and form a continuous series, whereas 

 the specific forms of life which are subject 



to them on the whole form a discontinuous 

 series." We should question this latter 

 statement. We have, for example, the two 

 great provinces of land and water ; we have 

 also marked and emphatic divergencies in 

 these larger provinces ; the deep, moist canon 

 in an arid plain, the sharp line between light 

 and darkness with their appropriate forms 

 salt and fresh water, with the intermediate 

 brackish water and the paucity of brackish 

 water forms, and these pointing to their 

 evident origin and subsequent adaptation ; 

 and rivers flowing through limy and gran- 

 itic regions, with examples of mud lakes, sand 

 lakes, and salt lakes. Indeed, the zones of 

 demarcation are often so narrow that the 

 varieties due to these selective features 

 struggle almost hopelessly to keep up an 

 existence. 



Mr. Bateson seems to think that physical 

 environment is the only selective action in 

 the struggle for existence ; but to those who 

 have studied Darwin there are many other 

 features to be taken into account, of which 

 no mention is made. Ignoring the theory of 

 natural selection, but recognizing the prime 

 importance of variation as the essential phe- 

 nomenon of evolution, he says, " Variation, 

 in fact, is evolution." He overlooks the im- 

 portance of all other factors upon which the 

 theory of natural selection rests inheritance, 

 without which the theory would fall ; the nu- 

 merical proportion of individuals remaining 

 the same, without which fact it could not be 

 shown that an infinitely greater number of 

 individuals perish than survive. 



These equally important factors are laid 

 aside, and he emphasizes the statement that 

 variation, in fact, is evolution. This is as 

 logical as if one should say evolution could 

 not exist without life, life could not exist 

 without oxygen (omitting certain forms of 

 bacilli), and hence oxygen is evolution. 



He repudiates the law of Von Baer, and 

 says " it has been established almost entirely 

 by inference, and it has been demonstrated 

 in scarcely a single instance." Mr. Bateson 

 can not understand why one species of moth 

 differs a little in pattern from another spe- 

 cies. He can not understand the utility of 

 small differences which distinguish species. 

 In his regard for species he should be re- 

 minded of the large number of species for- 

 merly considered good which have merged 



