August 8, 1913] 



SCIENCE 



177 



ravel the complex histological tangle of the 

 cerebrum and analyze the physico-chemical 

 processes that take place therein when it is 

 active, consciousness will remain incompre- 

 hensible on such a basis. I have been told of 

 a man who was working on the physical-chem- 

 istry of instinct. I feel sure our psychological 

 friends would reject with laughter such a 

 thesis ; they might perhaps accept it if it were 

 worded as the physico-chemical processes under 

 lying instinct. Tou can not analyze the pat- 

 tern by analyzing the component threads, al- 

 though that might help you in the end toward 

 fully understanding the pattern. I do not be- 

 lieve you can analyze the pattern of the life 

 activities in an organism, including of course 

 its " behavior," by analyzing the threads of 

 process that compose it. Try it, and I proph- 

 esy that failure will result, or you will resort 

 to the assumption of an autonomous vital prin- 

 ciple, as Driesch has done. Tou can not 

 analyze phenomena of one category in terms of 

 those of another. It is possible of course that 

 in time we shall know so much of the activity 

 pattern of organisms and how it was evolved 

 that we shall be able to solve the problem of 

 life, but I do not believe the explanation is so 

 close at hand as some would have us believe, 

 and perhaps we shall never know from inabil- 

 ity to unravel the past. 



Tou may gather from what I have just said 

 that so far from regarding those of you work- 

 ing along ecological lines, as I know some of 

 you are, as straying from the road that leads 

 toward the explanation of life, I would con- 

 sider you as pursuing lines of work in a field 

 peculiarly biological for which I know of no 

 broader and better term than that proposed 

 by Minot — bionomics. My only comment is 

 that such work should be analytical and not 

 merely descriptive, and you can not neglect 

 the texture of the fabric in tracing the pattern. 



I have now, I fear, gone far afield ia laying 

 before you my attitude toward adaptation and 

 have little time in which to present one or 

 two aspects of the subject that are of interest 

 to the embryological worker and to you as 

 members of a peculiarly bionomie club, if you 

 will let me use the term. If in the following 



I speak of adaptation, fitness, function, pur- 

 pose, I shall do so for simplicity's sake to avoid 

 complicated paraphrases, using them as pat- 

 tern terms solely. As one who is particularly 

 interested in the analysis of structure, I can 

 not but feel the all-pervading element of fit- 

 ness — adaptation — in structure, and the im- 

 portance of having a clear conception of what 

 it stands for when interpreting structure. 

 Whatever portion of the organism you 

 select for critical examination offers illus- 

 tration many-fold, so that I have been puzzled 

 that the existence (not interpretation) of adap- 

 tation can be questioned. There are, how- 

 ever, structures in the vertebrate body, as you 

 doubtless know, in which adaptation does not 

 stand revealed; I refer to vestigial structures 

 which, however, stand for adaptations, not 

 present but past, and may be divided into two 

 somewhat distinct groups, of which I will 

 venture to present one or two illustrations. 

 Again I will recall familiar facts to you, from 

 a rather different point of view, perhaps. 



The past history of organisms is reflected, 

 however imperfectly, in their development. 

 Past adaptation patterns, no longer applicable, 

 continue over. They may, or may not, play a 

 part in meeting the life condition complex 

 with which that organism is interwoven. The 

 quality of fitness in them may exist or appear 

 to be quite lacking. Numerous illustrations 

 may be chosen from the embryology of verte- 

 brates which are thoroughly familiar to you. 

 The development of the branchial chamber, 

 expressing a fundamental adaptation pattern 

 in the lower vertebrates, subserves no such 

 useful purpose in the higher forms. In con- 

 nection with it come certain intensely inter- 

 esting structures in which adaptation may or 

 may not be revealed. I can not appreciate the 

 functional importance of the thymus coming 

 from the third branchial pouch, nor of the 

 similar structure occasionally developing from 

 the branchial chamber farther back. To me 

 the tonsils have no deep hidden part to play 

 in the bodily economy but, useless and in some 

 cases detrimental, stand for a tiny portion of 

 an adaptation that is past. No specific func- 

 tions have been revealed; but in saying this. 



