480 The American Naturalist. [June, 
dynamics of living matter, is the utter impossibility of draw- 
ing a sharp line between the internal and the external. The 
functional organism is constantly acted upon by the environ- 
ment, and is incapable of existence apart from it. But the 
functional organism is but the ensemble of the functional parts, 
and the parts are linked functionally together, constantly act- 
ing and reacting upon each other and modifying each other’s 
work. It follows that the innermost portions cannot free 
themselves from environmental influence, and the attempt at 
an essential separation of internal from external physiology is 
in vain. Nor is such an attempt justified any the more by 
methods of investigation. For he who studies the action of 
light upon the retina, is thereby fitted to investigate the helio- 
tropic phenomena of the organism; and he who is familiar 
with methods by which the effect of salts or temperature on 
the organs is tested, is most capable of testing the influence 
of the composition and the temperature of the surrounding 
water upon aquatic animals and plants. I speak of this the 
more especially because of the fact that, since the comple- 
tion of the greater portion of this paper, the able address of ° 
Professor Burdon Sanderson, as President of the British Asso- 
ciation for the Advancement of Science, has appeared.’ In an 
interesting manner Professor Sanderson reviews the aspects of 
physiology since the time of Müller. He says, “The distinc- 
tio * * * * between the internal and external relations: 
of plants and animals has, of course, always existed, but has 
only lately come into such prominence that it divides biolo- 
gists 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 investigation as far as the conditions 
under which each process manifests itself will permit; on the 
other, those who interest themselves rather in considering 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 oF 
ganism does, rather than to what it is, and therefore both have 
§ Nature, September 14, 1893. 
