190 THEORY OF THE CELLS. 
are essentially the same for all elementary parts. One can 
see no reason why this should be the case, if each organism be 
endued with a special power to frame the parts according to 
the purpose which they have to fulfil: it might much rather 
be expected that the formative principle, although identical 
for organs physiologically the same, would yet in different 
tissues be correspondingly varied. This resemblance of the 
elementary parts has, in the imstance of plants, already led to 
the conjecture that the cells are really the organisms, and that 
the whole plant is an aggregate of these organisms arranged 
according to certain laws. But since the elementary parts of 
animals bear exactly similar relations, the mdividuality of an 
entire animal would thus be lost; and yet precisely upon the 
individuality of the whole animal does the assumption rest, that 
it possesses a single fundamental power operating in accordance 
with a definite idea. 
Meanwhile we cannot altogether lay aside teleological views 
if all phenomena are not clearly explicable by the physical view. 
It is, however, unnecessary to do so, because an explanation, 
according to the teleological view, is only admissible when the 
physical can be shown to be impossible. In any case it con- 
duces much more to the object of science to strive, at least, to 
adopt the physical explanation. And I would repeat that, 
when speaking of a physical explanation of organic phenomena, 
it is not necessary to understand an explanation by known 
physical powers, such, for instance, as that universal refuge 
electricity, and the like; but an explanation by means of 
powers which operate like the physical powers, in accordance 
with strict laws of blind necessity, whether they be also to be 
found in inorganic nature or not. 
We set out, therefore, with the supposition that an organized 
body is not produced by a fundamental power which is guided 
in its operation by a definite idea, but is developed, according 
to blind laws of necessity, by powers which, like those of 
inorganic nature, are established by the very existence of 
matter. As the elementary materials of organic nature are 
not different from those of the morganic kingdom, the source 
of the organic phenomena can only reside in another combi- 
nation of these materials, whether it be in a peculiar mode of 
union of the elementary atoms to form atoms of the second 
