404 ANNUAL EEPOKT SMITHSONIAN INSTITUTION, 1915. 



sequences in respect to the nature of evolution. Are Ave not then 

 invited to strain at a gnat and to swallow a camel ? 



But I pass over the technical basis of the conception in order to 

 look more broadly at its theoretic superstructure. Is not this, once 

 again, a kind of symbolism by which the endeavor is made to deal 

 with a problem that is for the present out of our reach? Neither 

 you nor I, I dare say, wall hesitate to maintain that the primordial 

 Amoeba (if we may so dub the earliest of our ancestors) embodied in 

 some sense or other all the potentialities, for better or for worse, 

 that are realized before us at this moment in the American Associa- 

 tion for the Advancement of Science. But if we ask ourselves exactly 

 what we mean by this w'e discover our total inability to answer in 

 more intelligible terms. 



We can not, it is true, even if we would, conquer the temptation now 

 and then to spread the wings of our imagination in the thin atmos- 

 phere of these upper regions ; and this is no doubt an excellent tonic for 

 the cerebrum provided we cherish no illusions as to what w^e are about. 

 No embryologist, for example, can help puzzling over what I have 

 called the problem of the microcosm ; but he should be perfectly well 

 aware that in striving to picture to his imagination the organization 

 of the egg, of the embryological germ, that is actually in his hands 

 for observation and experiment, he is perilously near to the habitat 

 of the mystic and the transcendalist. The student of evolution is 

 far over the frontier of that forbidden land in any present attack 

 upon the corresponding problem of the macrocosm, for the primor- 

 dial Amceba, the evolutionary germ, is inconceivably far out of our 

 reach, hidden behind the veil of a past wdiose beginnings lie Avholly 

 beyond our ken. And why, after all, should w^e as yet attempt the 

 exploration of a region which still remains so barren and remote? 

 Surely not for the lack of accessible fields of genetic research that 

 are fertile and varied enough to reward our best efforts, as no one 

 has more forcibly urged or more brilliantly demonstrated by his 

 own example than Prof. Bateson himself. 



Perhaps it would be the part of discretion to go no further. But 

 the remarkable questions that Prof. Bateson has raised concerning 

 the nature of evolution leave almost untouched the equally mo- 

 mentous problem as to what has guided its actual course. In ap- 

 proaching my close I shall be bold enough to venture a step in this 

 direction, even one that will bring us upon the hazardous ground of 

 organic adaptations and the theory of natural selection. I need not 

 say that this subject is beset by intricate and baffling difficulties 

 which have made it a veritable bone of contention among natural- 

 ists in recent years. In our attempts to meet them we have gone to 

 some curious extremes. On the one hand, some naturalists have in 

 effect abandoned the problem, cutting the Gordian knot with the 



