86 THE CELL DOCTRIN-B. * 



but which alone of the elements of this cell we are in 

 the habit of calling " nucleus." The " nucleus" then, 

 is nothing but a new centre of germinal matter, and 

 the " nucleolus " is a younger centre. And there may 

 even be within this a still younger portion of living 

 matter, taking even a deeper stain, which might be 

 called a " nucleoleolus." By this staining process may 

 we distinguish the nucleolus from a minute oil-drop 

 often mistaken for it, and which will not admit of 

 being stained. 



On the other hand, germinal matter in a compar- 

 atively quiescent state is often quite destitute of 

 nuclei. But let the mass be freely supplied with nu- 

 trient matter, and nuclei and nucleoli rapidly make 

 their appearance. 



So with regard to the " cell contents " over and 

 above the nucleus, although they may all be germinal 

 matter, yet this is not necessarily the case. Thus 

 in the white blood-corpuscle and mucus-corpuscles, 

 what Virchow would consider cell contents is all ger- 

 minal matter ; but the superficial epithelial cell lining 

 the interior of the mouth has its nucleus alone com- 

 posed of germinal matter, and much that has been 

 described as cell contents is really formed matter. 

 (Figs. 5 and 6 of frontispiece.) More nearly does the 

 germinal matter of Beale* correspond with the "proto- 

 plasm " of Max Schultze, with which , indeed , it seems 

 identical, except that the latter observer seems some- 

 what at a loss how to dispose of the nucleus, of 



* Beale, Protoplasm; or, Life, Force, and Matter. London, 

 1870, p. 38. 



