" ARBOREAL MAN " 231 



are not necessarily grasped solely, or to the full, by the animal which 

 becomes most completely specialised. 



But we have concluded that the most ideal specialisation is 

 that of the animal which is the most harmoniously and the most 

 usefully inter-related to the rest of strenuous organic life ; and 

 such an animal is by the very fact of this interaction precluded 

 from making faulty adaptations. 



The author here loses himself in the abysses of " Contre- 

 E volution," after the fashion of the " Biologiste naif," and, 

 after what has been said on the subject in previous chapters, I 

 need not follow him further along this track. To one remark 

 of his, however, I shall have to add a strong rider, namely, 

 with regard to " specialisation to an exclusive diet." 



Such a diet, he thinks, has proved the downfall of many a 

 promising animal type, and he instances a " specialisation " for 

 blood-sucking, or for ant-eating in significant contrast to those 

 other feeding habits which, on my interpretation, stand out 

 prominently throughout the book as favourable to success, 

 namely, those which I have termed " cross-feeding." Obviously 

 this matter cannot be treated in a discursive manner, and without 

 answering the questions : what constitites an " exclusive," and 

 what a " normal " or " ideal " diet. The author's predicament, 

 of course, is that nutrition is still largely a terra incognita of 

 science. De hoc multi multa, omnis aliquid, nemo satis. 



With almost incredible levity, he makes the transition from 

 the unsuccessful blood-sucker and the equally unsuccessful 

 ant-eater to the immensely successful Primate stock, the triumph 

 of which is suddenly to be accounted for by " non-specialisation 

 in diet," i.e., by a combination of carnivorism with frugivorism 

 or herbivorism : 



The Primate and human stock has not been led astray in this direction ; 

 for it has preserved throughout that well-balanced habit of dietary, only 

 to be termed omnivorous. 



It is satisfactory to find that it has at last dawned upon the 

 author that food-adaptation is all-important. It is at least a 

 good beginning. But is seems rather arbitrary, if not unkind, 

 to saddle the Primate stock with omnivorism, when, throughout 

 the story, the most was made, and rightly so, of its successful 

 ventures and transactions with fruits and seeds. I strongly 

 demur to the view that an omnivorous diet is a " well-balanced 

 habit of dietary," which is based upon prejudice rather than 



