THE CELL DOCTRINE, 59 



entiation is accomplished. This principle, which is here 

 referred to as the " vis essentialis," is elsewhere in- 

 cluded under the expressions " vitality," and " general 

 determining laws of the organism." Though this ad- 

 mission is seemingly so at variance with the views of 

 the same observer in 1870, when, in common with 

 other physicists, he emphatically denied the exist- 

 ence of " vital force," or even such a thing as life 

 itself, yet, as already intimated, we deem it possible 

 to detect a foreshadowing of his more modern views, 

 in the following paragraph of the paper whence we 

 have derived our information : 



" We have therefore maintained the broad doctrine 

 established by Wolft", that the vital phenomena are 

 not necessarily preceded by organization, nor are in 

 any way the result or effect of formed parts, but 

 that the faculty of manifesting them resides in the 

 matter of which living bodies are composed, as such ; 

 or, to use the language of the day, that the, vital 

 forces are molecular forces"* 



Huxley moreover says that the three botanical 

 data upon which Schwann's theory was based, viz. : 



1. The anatomical independence of the vegetable 

 cell as a separate entity. 



2. His conception of the structure of the vege- 

 table cell, and 



3. Its mode of development, were all erroneous. 

 Since first, he (Huxley) considers that the fact 



that by certain chemical or mechanical means, a 

 plant may be broken up into vesicles, corresponding 



* Huxley, loc. citat., p. 314. 



