BOOKS REVIEWED. 



273 



" Heredity." By C. W. Saleeby, M.D. 8vo., 11G pp. (T. C. & E. C. 

 Jack, London and Edinburgh.) Is. net. 



This book contains fourteen chapters, on such questions as " The 

 Modes of Reproduction," " The Facts and Functions of Sex," " Biometric 

 Study of Heredity," the "Origin of Variation, Mendelism, &c." It is an 

 excellent resume of various writers' views on the subject treated of, but 

 there are some expressions and matters to which we must take exception. 



On p. 12, the author says "Variation cannot be reduced to law." 

 Though it is impossible to explain how Life makes variations in structure, 

 the "Law" is patent enough, viz. that variations arise in direct response 

 to new conditions of life : that is, there is a direct relationship between 

 the new structures and the new conditions : whereas in Darwinism there 

 is none ; just as there is none between fragments of a rock broken off by 

 the frost, and the house a man may build with them.* Hence, we quite 

 agree with Dr. Saleeby in saying " there is clear evidence of Purpose 

 behind things." 



We are glad to see the vigorous way he exposes and refutes Weismann's 

 theories, as, e.g., " biparental reproduction is a means of preserving the 

 racial type." Geology shows that in due course "racial types" vanish 

 just as individual types do. 



The author says : " This theory of natural selection is now a truth 

 questioned by no competent and very few incompetent critics." It is un- 

 fortunate that Dr. Saleeby has not studied the writings of present-day 

 ecologists ; had he done so he would scarcely have included Dr. Warming 

 as "incompetent," who writes : " I answer briefly to the question which 

 arises, namely, whether these adaptations to the medium should be 

 regarded as a result of natural selection, or whether they owe their origin 

 to the action, in modifying forms, exercised directly by the conditions of 

 the medium. I adopt this latter view. . . . The characters of adaptation 

 thus directly acquired have been fixed." 



Dr. Saleeby has here fallen into the common mistake, of assuming as 

 non-existent what happens not to be known by himself. 



" Organic Evolution." By C. W. Saleeby, M.D. 8vo., 124 pp. 

 (T. C. & E. C. Jack, London and Edinburgh.) Is. net. 



This little book contains fifteen chapters dealing with the Factors of 

 Evolution, the Evolution of Plants, and Man and his future Evolution, &c. 

 He alludes to Malthus's "Essay on Population" as having suggested 

 "Natural Selection" to Darwin, and observes that the fleeter and the 

 stronger and the craftier animals would be selected, if food were insufficient 

 for all. So far, this is true ; but it only refers to the distribution by 

 survival, not the origin of species. The question is — which Darwin 

 avoided — how came one to be so fleet, or so strong, or so crafty ? 



Darwin's and Wallace's papers were quite distinct, not " a joint paper " 

 as the author imagines. Moreover, while Darwin based his theory on 

 "Animals and Plants under Domestication," in his own paper Wallace 

 says it is impossible to do so. 



With regard to natural selection he rightly observes that (as Darwin 



* This is Darwin's simile, An. & PI. under Bom. ii. 431. 



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