CHAPTER I 



INTRODUCTORY I THE BASAL PROBLEM OF EVOLUTION 



I HAVE selected this subject of Adaptation and Disease, not 

 merely because of its importance to physicians, but also, and 

 to an even greater extent, because of its broad biological signifi- 

 cance. The time is ripe, and more than ripe, for attention to 

 be directed to the bearing of the investigations of the bacterio- 

 logist on the one hand, and of the student of immunity on the 

 other, upon what are some of the most important problems of 

 general biology. For some little time I have been impressed 

 by the fact that the latter-day investigations in medical science 

 are of the very highest significance to the general biologist, 1 

 and that with singularly rare exceptions the professional biologist 

 be he zoologist or botanist has been superbly indifferent to 

 them and to their bearing upon the basal problems of heredity 

 and variation, and this notwithstanding the fact that investiga- 

 tions into heredity and variation are, and must always be, his 

 greatest concern. 



For this indifference and neglect there are, or may be, several 

 extenuating circumstances. We ourselves are largely to blame 

 in that we are more concerned with the bearing of our results 

 upon our own medical work than with their wider biological 

 significance. This wider significance, if it is referred to at all, 

 finds incidental note. The titles of our articles, that is, are 

 not such as attract the attention of the biologist, nor do we 

 publish in the journals to which he is addicted. Not to mention 

 foreign publications, the Journal of Pathology and Bacterio- 

 logy, the Journals of Experimental Medicine, of Hygiene, In- 



1 Five years ago this was the subject of my opening address as President of 

 the 'Biological Section of the Royal Society of Canada. Trans. Boy. Soc. 

 Canada, 3rd series, 1912, vol. vi. section 4, p. 1. 



