ADDRESS. 7 



distinguishable into two kinds, according as we consider the action of 

 the whole organism in its relation to the external world or to other 

 organisms, or the action of the parts or organs in their relation to each 

 other. The distinction to which we are thus led between the infernal 

 and external relations of plants and animals has of course always existed, 

 but has only lately come into such prominence that it divides biologists 

 more or less completely into two camps — on the one hand those who 

 make it their aim to investigate the actions of the organism and its parts 

 by the accepted methods of physics and chemistry, carrying this investi- 

 gation as far as the conditions under which each process manifests itself 

 will permit ; on the other those who interest themselves rather in con- 

 sidering the place which each organism occupies, and the part which it 

 plays in the economy of nature. It is apparent that the two lines of 

 inquiry, although they equally relate to what the organism does, rather 

 than to what it is, and therefore both have equal right to be included in 

 the one great science of life, or biology, yet lead in directions which, 

 are scarcely even parallel. So marked, indeed, is the distinction, that 

 Professor Haeckel some twenty years ago proposed to separate the study 

 of organisms with reference to their jolace in nature under the designa- 

 tion of ' oecology,' defining it as comprising ' the relations of the animal 

 to its organic as well as to its inorganic environment, particularly its 

 friendly or hostile relations to those animals or plants with which it 

 conies into direct contact.' • Whether this term expresses it or not, the 

 distinction is a fundamental one. Whether with the cecologist we 

 regard the organism in relation to the world, or with the physiologist as 

 a wonderful complex of vital energies, the two branches have this in 

 common, that both studies fix their attention, not on stuffed animals, 

 butterflies in cases, or even microscopical sections of the animal or plant 

 body — all of which relate to the framework of life — but on life itself. 



The conception of biology which was developed by Treviranus as far 

 as the knowledge of plants and animals which then existed rendered 

 possible, seems to me still to express the scope of the science. I should 

 have liked, had it been within my power, to present to you both aspects 

 of the subject in equal fulness ; but I feel that I shall best profit by the 

 present opportunity if I derive my illustrations chiefly from the division of 

 biology to which I am attached — that which concerns the internal rela- 

 tions of the organism, it being my object not to specialise in either 

 direction, but, as Treviranus desired to do, to regard biology as part — 

 surely a very important part — of the great science of nature. 



The origin of life, the first transition from non-living to living, is a 



' These he identifies with 'those complicated mutual relations which Darwin 

 designates as conditions of the struggle for existence.' Along with chorology — the 

 distribution of animals — oecology constitutes what he calls Relatiotis-Physiologie. 

 Haeckel, 'Entwickelungsgang u. Aufgaben der Zoolo^e, ' Jenaische Zeitschr., vol. v. 

 1869, p. 353. 



