n 



THE BEGINNINGS OF II FE: 



149 



of 



source 



views 



hoi 



ogical k. 



e 



) 



nedicin 



' the ultimatt 



ny manifesta. 



°r the seat o[ 



But then lit 



wco in b: 



i bed by Schlei 



ced only 

 r, he does 

 ■ the tissues is 

 the existeMt 

 erial in 



IS 



jt 



ter 



fact with l!! 

 forward 



ial niay 

 each 



tt 



)ries, 



m 



middle of it.' He also is disposed to attach much 

 importance to the nucleus, and believes that ^as long 

 as cells behave as elements still endowed with vital 

 power^ the nucleus maintains a very constant form/ 

 Thus^ according to Virchow, ^ every animal presents 

 Itself as a sum of vital unities^ or as a large kingdom 

 made up of an enormous aggregate of minute depend- 

 encies^ each of which is endowed with more or less 

 power of self-government — these dependencies being 

 invariably constituted by definite morphological units 

 known as cells^ though there may or may not be in- 

 cluded under the sway of each a certain outlyin 

 *^cell territory/ Such is the essence of Virchow's 

 doctrine. 



rf 



Before proceeding further^ however, it will be well 

 to point out that important modifications had been 

 growing up, even before the publication of Virchow's 

 theories, as to the true conception of the nature of a 

 cell. So far the cell has been spoken of as an alto- 

 gether definite structure — as a body with a distinct wall 

 or bounding membrane and also certain contents, which 

 include amongst other things one of the most funda- 



which again 





mental parts of the cell, the nucleus 



may contain a nucleolus. But it was maintained by 



Naeffeli ^. and also hv Alpvanrlpr Rmnn 2 rsr\c\ thpn morp 



or 



vital P 



m^ 



ch, 



tliis 



bol<l^ 





 







si^! ■ 



^ 'Zeitschrift fiir Wissen. Botanik/ 1846 (Transln. Ray Soc. 1849, 



P-95). 



^ 'The Phenomena of Rejuvenescence in Nature,' 1851 (Transln. 

 Ray Soc. 1853), 



