January 20, 19 16] 



NATURE 



561 



"VIGOUR" AND "INSTINCT." 

 (i) Vigour and Heredity. By J. L. Bonhote. 

 Pp. xii+263. (London: West, Newman and 

 Co., 1915.) Price 105. 6d. net. 

 P (2) Instifict and Intelligence. By N. C. Mac- 

 namara. Pp. 216. (London: Henry Frowde 

 and Hodder and Stoug-hton, 191 5.) Price 65. 

 net. 



(i) T N his experience as a breeder and naturalist 

 X Mr. Bonhote has been confronted with 

 the difficulties presented by many of the facts of 

 inheritance. Mendel's law holds gfood in some 

 cases, Gallon's law in others, but many facts 

 seem unconformable, and a consideration of these 

 has led him to a theory of "vigour." By vig-our 

 he means " activity of nutrition and function " or 

 "the rate of metabolism," and his theory is that 

 the "initial vigour" of an organism, which in 

 part determines the expression of its inheritance, 

 depends upon the vigour of the parents at the 

 time of reproduction. 



The author is in error in thinking that "we 

 have no method of definitely ascertaining or 

 measuring the rate of metabolism," for we can 

 use the absorption of oxygen or the output of 

 carbon dioxide as an index. In default of this, 

 an attempt is made to estimate vigour indirectly 

 "by actions, colour, and condition," and this 

 means slippery ground on which the author does 

 not always keep his feet. By a multitude of in- 

 teresting illustrations, however, he seeks to show 

 that temperature, humidity, and food supply in- 

 fluence vigour, and through vigour coloration. 

 Thus colour becomes "our best and at the present 

 time our chief index of vigour." It is plain, how- 

 ever, that a brief intensity of metabolism might 

 lead to an abundant production of pigment, and 

 that the organism might thereafter settle down to 

 a humdrum sluggishness indicative of anything 

 but vigour. 



Mr. Bonhote adopts the reasonable view that 

 a radical physiological difference in metabolism 

 distinguishes the sexes, but he states the idea too 

 crudely when he simply calls the male katabolic 

 and the female anabolic. According to "The 

 Evolution of Sex" (1889), to which he refers 

 many times, the fundamental physiological 

 difference between the sexes lies in the 

 relative predominance of anabolism or kata- 

 bolism in the metabolic processes. Constructive 

 processes, notably those that have to do with 

 the upbuilding of proteids, must, of course, 

 always exceed disruptive processes so long as the 

 organism continues to be a going concern, but the 

 " Evolution of Sex " thesis was that the ratio of 

 anabolism to katabolism is characteristically 

 I NO. 2412, VOL. 96] 



greater in females than in males, and conversely. 

 Mr. Bonhote prefers to conceive of the funda- 

 mental difference as depending on the rate of 

 intensity of metabolism, and unfortunately he 

 sometimes uses the concept of metabolism too 

 narrowly {e.g., on p. 244), as if it had simply to 

 do with assimilation processes. In this con- 

 nection it may be noted that, according to the 

 author, high vigour in the parents tends to a pre- 

 dominance of females among the offspring 

 (though the opposite seems to have been inad- 

 vertently stated in the last sentence of chapter v.). 



The central idea of the book is that the en- 

 vironment in the widest sense affects vigour (de- 

 fined as rate of metabolism), that the vigour of 

 the parents at the time of reproduction " is re- 

 flected to a greater or less extent in the vigour " 

 (here used in a rather different sense !) of the 

 sex-cells, and therefore in the vigour of any deter- 

 minant in the inheritance. The development of 

 characters is thus influenced by the vigour of the 

 parents, and also, the author maintains, by the 

 nurture (in the widest sense) of the developing 

 individual. Mr. Bonhote knows that he has not 

 proved his theory, and we are afraid that it will 

 not admit of proof until its terms are made more 

 precise, but attention must be directed to the 

 hundred pages in which the author describes his 

 breeding experiments, conducted con amore and 

 under difficulties, on goats, cats, rats, pigeons, 

 and ducks (of which there are three very fine 

 plates), and expounds without any dogmatism the 

 facts that have led him to the conviction that 

 environment affects the physiologicai condition of 

 the parent, and may have some influence on the 

 characters of the off'spring. 



(2) Dr. Macnamara takes an interesting survey 

 of the chief modes of animal behaviour, and shows 

 how much there is — from amoeba to man — that 

 deserves to be called purposive, though it cannot 

 be called intelligent. In the higher animals the 

 hereditarily engrained instinctive capacities have 

 their seat in the basal ganglia, while the intelli- 

 gent capacities are localised in the upper regions 

 of the cerebral cortex, notably in the "neopal- 

 lium " of mammals. The author's thesis is that 

 in human education too little attention is given 

 to the phylogenetically older instinctive impulses 

 and emotions, and relatively too much to trying 

 (not very successfully) to train the intellect. What 

 he advises is that more care should be given to 

 discovering what in each child are the strongest 

 instinctive qualities and adjusting the education 

 thereto ; that teachers should know more about 

 the physiology of the nervous system ; that there 

 should be more sensory experience at a high 

 level; that exercises in control should be devised; 



