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 instance 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 individuality 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 inorganic 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 



