6 KEPOET 1893. 



The purpose which I have in view in taking yon back as I have done 

 to the beginning of the century is not merely to commemorate the work 

 done by the wonderfully acute writer to whom we owe the first scientific 

 conception of the science of life as a whole, but to show that this con- 

 ception, as expressed in the definition I have given you as its foundation, 

 can still be accepted as true. It suggests the idea of organisin as that to 

 which all other biological ideas must relate. It also suggests, although 

 perhaps it does not express it, that action is not an attribute of the 

 organism but of its essence — that if, on the one hand, protoplasm is the 

 basis of life, life is the basis of protoplasm. Their relations to each 

 other are reciprocal. We think of the visible structure only in con- 

 nection with the invisible process. The definition is also of value as 

 indicating at once the two lines of inquiry into which the science has 

 divided by the natural evolution of knowledge. These two lines may be 

 easily educed from the general principle from which Treviranns started, 

 according to which it is the fundamental characteristic of the organism 

 that all that goes on in it is to the advantage of the whole. I need 

 scarcely say that this fundamental conception of organism has at all 

 times presented itself to the minds of those who have sought to under- 

 stand the distinction between living and non-living. Without going 

 back to the true father and founder of biology, Aristotle, we may recall 

 with interest the language employed in relation to it by the physiologists 

 of three hundred years ago. It was at that time expressed by the term 

 consensus partium — which was defined as the concurrence of parts in 

 action, of such a nature that each does qitod suum est, all combining 

 to bring about one eSect ' as if they had been in secret council,' but at 

 the same time cunstanti quadaw, naturoi lerjo} Professor Huxley has 

 made familiar to us how a century later Descartes imagined to himself a 

 mechanism to carry out this consensus, based on such scanty knowledge 

 as was then available of the structure of the nervous system. The dis- 

 coveries of the early part of the present century relating to reflex action 

 and the functions of sensory and motor nerves, served to realise in a 

 wonderful way his anticipations as to the channels of influence, afferent 

 and efferent, by which the consensus is maintained ; and in recent times 

 (as we hope to learn from Professor Horsley's lecture on the physiology 

 of the nervous system) these channels have been investigated with 

 extraordinary minuteness and success. 



Whether with the old writers we speak about co^isensus, with Treviranus 

 about adaptation, or are content to take organism as our point of departure, 

 it means that, regarding a plant or an animal as an organism, we concern 

 ourselves primarily with its activities or, to use the word which best ex- 

 presses it, its energies. Now the first thing that strikes us in beginning 

 to think about the activities of an organism is that they are naturally 



' Bausner, De Consensu Partivm Hvmani Corjjoris, Amst., 155C, Pnef. ad lec- 

 torem, p. 4. 



