254 THE CELL-THEORY 





the union and combined action of these primarily separate elements. 

 Wolff, on the other hand, asserts that the primary histological elements 

 (cells too, but not always defined in the same way) are not either 

 anatomically or physiologically independent ; that they stand in the 

 relation of effects to the organizing or vital force (vis essentialis) ; and 

 that the organism results from the " differentiation " of a primarily 

 homogeneous whole into these parts. Such a doctrine is, in fact, a 

 most obvious and almost a necessary development of the doctrine of 

 ■'^ epigenesis in general. VTo one who had worked out the conclusion, 

 '"' V that the most complex, grosser, animal or vegetable organizations, arise 

 ^ ^' from a semi-fluid and homogeneous mass, by the continual and 

 ^ successive establishment of differences in it, it would be only natural 



^ fl to suppose that the method of nature, in that finer organization which 

 £'' J S X ^Ave call histological, was the same ; and that as the organ is developed 

 ^ =^^ ^' by the differentiation of cells, so the cells are the result of the differen- 

 s* ^ . jtiation of inorganic matter. If the organism be not constituted by 



, <f 'V" the coalescence of its organs and tissues in consequence of their peculiar 

 forces, but if, on the other hand, the organism exists before its organs 

 ;and tissues, and evolves them from itself, — is it not probable that the 

 ■organs and tissues also, are not produced by the coalescence of the 

 yv- cells of which they are composed, in consequence of their peculiar 



^ " forces, but, contrariwise, that the cells are a product of the differentia- 



tion of something which existed before them ? \ 



For Schwann the organism is a beehive, its actions and forces 

 resulting from the separate but harmonious action of all its parts 

 (compare Schwann, 1. c, p. 229). For Wolff it is a mosaic, every 

 iportion of which expresses only the conditions under which the 

 formative power acted and the tendencies by which it was guided. 



We have said above, not without a full consciousness of the respon- 

 sibility of the assertion, that we believe the cell-theory of Schleiden 

 and Schwann to be based upon erroneous conceptions of structure, and 

 to lead to errors in physiology, and we beg now to offer some evidence 

 in favour of these views. We need not stop to prove, what must be 

 familiar to every one who is acquainted with Schwann's work, that in 

 making his comparison of animal with vegetable structures, he rests 

 wholly upon Schleiden's statements concerning the development, and 

 upon the commonly prevalent views with respect to the anatomy, of 

 the latter. 



It is clear, then, that however logically consequent Schwann's work 

 may be in itself, its truth and the justice of its nomenclature will depend 

 upon that of these latter views and statements. Schwann took these 



