60 VITALISM AND SCHOLASTICISM 



nucleus get on without the cell, for it too 

 perishes if it be cut off completely from it. It 

 seems as if the cytoplasm, or cell-protoplasm 

 in some way acts as a stimulant to the nuclear 

 protoplasm and hence, though the nucleus is, 

 or appears to be, the main factor in division, 

 it is possible that the cytoplasm may " in- 

 directly regulate the process of cleavage."* 



Cytoplasm then is necessary to nucleus and 

 nucleus to cytoplasm. If a unicellular organism 

 be so divided up that certain of the fragments 

 into which it is separated contain portions of 

 the nucleus and certain do not, those fragments 

 which contain bits of the nucleus will continue 

 to live and what is more will gradually recon- 

 struct themselves so that each of them will 

 become a new organism. But not so the bits 

 which have not been fortunate enough to 

 secure a fragment of nuclear substance. As 

 above stated these portions linger for a time 

 with some of the signs of life but ultimately 

 die. 



Hence we may conclude with Balbiani t that 

 " the cellular life neither resides exclusively in 

 the protoplasm [i.e., cytoplasm or cell-proto- 

 plasm as opposed to nucleoplasm] nor within 

 the nucleus, but results from the reciprocal 



* Morgan, The Development of the Frog's Egg, p. 128. 

 t Annales de Micrographie, 1893. 



