Cells Become Differentiated and Somatized 83 
possible to put it in conditions which would render it 
capable of nourishing itself and preserving its life 
independently separated from the rest of the organism, 
could function as a germ cell.5? 
And certain processes which appear in all the lower 
organisms, with tissues that are not very highly 
specialized, appear to justify this view. 
If one places a piece of a Begonia phyllomaniaca in 
some earth in moist air, after cutting through the leaf- 
ribs in different places, one finds after some time, in the 
neighborhood of each wound, one or more little new 
plants. Any fragment whatever of a hydra or medusa 
possesses the power of reforming an entire animal 
without increasing its mass, but rather by a process of 
differentiation and rearrangement of cells already existing. 
A theory which admits equal nuclear division and also 
a slow and gradual nuclear somatization, resulting from 
the action of a determinate zone constituted only by the 
germinal substance, would reconcile the different and 
contradictory phenomena brought forward by the epi- 
genesists on the one side, and by the preformists on the 
other. 
Oscar Hertwig who as we have just seen is a zealous 
partisan of the idioplasmic equality of all nuclei, is com- 
mitted in another place to the possibility of a certain 
nuclear somatization. “The hypothesis of a hereditarily 
equal nuclear division does not imply the view that the 
‘anlage’ substance must therefore be an immutable 
thing. . . . The idioplasms of certain groups of cells 
of an organism which find themselves permanently in 
unlike conditions in consequence of their different spatial 
and functional disposition in the body as a whole, dif- 
®Qscar Hertwig: Die Zelle und die Gewebe. Zw. Buch. P, 
304—305. 
