460 BIOLOGY IN RELATION TO OTHER NATURAL SCIENCES. 



being' made to establish in Euglaiid an institution for this ])urpose, not 

 interior in elilicieney to thoseof other countries, may have the sympathy 

 of all present? And now may 1 ask your attention for a few moments 

 more to the subject that more immediately concerns usf 



CONCLUSION. 



The purpose which I have had in view has been to show that there 

 is one principle — that of adaptation — which separates biology from the 

 exact sciences, and that in the vast field of biological inquiry the end 

 we have is not merely, as in natural philosophy, to investigate the rela- 

 tion between the phenomenon and the antecedent and concomitant con- 

 ditions on which it dei>ends, but to ])ossess this knowledge in constant 

 reference to the interest of the organism. It may i)erhaps be thought 

 that this way of putting it is too teleological, and that in taking-, as it 

 were, as my text this evening so old-fashioned a biologist as Trevira- 

 nus, I am yielding to a retrogressive tendency. It is not so. What I 

 have desired to insist on is that organism is a fact which encounters the 

 biologist at every step in his investigations; that in referring it to any 

 general biological principle, such as adaptation, we are only referring it 

 to itself, not explaining it; that no explanation will be attainable until 

 the conditions of its coming into existence can be subjected to experi- 

 mental investigation so as to correlate them with those of i:)iocesses in 

 the non-living world. 



Those who were present at the meeting of the British Association at 

 Liverpool, will remember that then, as well as at some subsequent 

 meetings, the question whether the conditions necessary' for such an 

 inquiry could be realized was a burning one. This is no longer the 

 case. The i)atient endeavors which were made about that time to 

 obtain experimental proof of what was called ^(/>iof/ewesis, although they 

 conduced materially to that better knowledge which we now possess of 

 the conditions of life of bacteria, failed in the accomplishment of their 

 purpose. The question still remains undetermined; it has, so to speak, 

 been adjourned sine Me. The only approach to it lies at present in the 

 investigation of those rare instances in which, alth<mgh the relations 

 bettveen a living organism audits environment ceases as a watch stops 

 when it has not been wound, these relations can be re-established — the 

 process of life re-awakened — by the application of the required stinuilus. 



I was also desirous to illustrate the relation between physiology and 

 its two neighbors on either side, natural philosophy (including chemis- 

 try), and psychology. As regards the latter, I need add nothing- to 

 what has already been said. As regards the former, it may be well to 

 notice that, although physiology can never become a mere branch of 

 applied physics or chemistry, there are parts of physiology wherein the 

 principles of these sciences may be applied directly. Thus, in the 

 beginning of the century, A'oung applied his investigations as to the 

 movements of liquids in a system of elastic tubes directly to the phe- 



