20 THE CELL DOCTRINE. 



Two points are here particularly to be observed as 

 cardinal, first, the non-independence of cells, either 

 anatomically or physiologically; that they are ef- 

 fects, passive results, and not causes of a vitalizing or 

 organizing force; second, that organization takes 

 place from the " differentiation " of the homogeneous 

 living mass in these parts, through the agency of the 

 vis essentialis or inherent vital force. The radical 

 difference between these principles of development 

 and those generally held at the present day, will be 

 better appreciated when these latter have been 

 worked out. An acknowledged error may also be 

 pointed out, the probable result of the inferiority of 

 the instruments of that day that of supposing the 

 cells of plants to communicate when in their youngest 

 state. 



This theory, however, full as it was of original 

 conception, and based on actual observation, seemed 

 to claim little attention, and would have been still 

 less known but for the labors of Prof. Huxley. The 

 " fibre" theory of Haller was still further expanded, 

 and that fibres were the groundwork of nearly all 

 the tissues, continued the prevailing view, until the 

 latter part of the eighteenth century, and there are 

 few of the older physiologies even of a later date, 

 which do not contain an account of it. Naturally, 

 it maintained itself longest in the case of the fibrous 

 tissues, since the appearances of these tissues, when 

 examined by the highest powers, are those of struc- 

 tures apparently composed of fibres. 



The reaction which took place at the date referred 

 to against the "fibre" theory, culminated in the 



