28 REPORT — 1893. 



inquiries have to go to Berlin, to Munich, to Breslau, or to the Pasteur 

 Institute in Pai-is to obtain what England ought long ago to have pro- 

 vided. For to us, from the spread of our race all over the world, the 

 prevention of acute infectious diseases is more important than to any 

 other nation. At the beginning of this address I urged the claims of 

 pure science. If I could, I should feel inclined to speak even more 

 strongly of the application of science to the discovery of the causes of 

 acute diseases. May I express the hope that the effort which is now 

 being made to establish in England an Institution for this purpose not 

 inferior in efficiency to those of other countries, may have the sympathy 

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

 more to the subject that more immediately concerns us ? 



CONCLBSION. 



The purpose which I have bad in view has been to sbow 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 relation 

 between a phenomenon and the antecedent and concomitant conditions 

 on which it depends, but to possess this knowledge in constant reference 

 to the interest of the organism. It may perhaps 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 Treviranus, 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 con- 

 ditions of its coming into existence can be subjected to experimental 

 investigation so as to correlate them with those of processes 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 meet- 

 ings, the question whether the conditions necessary for such an inquiry 

 could be realised was a burning one. This is no longer the case. The 

 patient endeavours which were made about that time to obtain experi- 

 mental proof of what was called abiogenesis, although they conduced 

 materially to that better knowledge which we now possess of the con- 

 ditions of life of bacteria, failed in the accomplishment of their purpose. 

 The question still remains undetermined ; it has, so to speak, been ad- 

 journed sine die. The only approach to it lies at present in the inves- 

 tigation of those rare instances in which, although the relations between 

 a living organism and its environment ceases as a watch stops when it 



