6j2 THE AMERICAN NATURALIST. [Vol. XXXVII. 



exactly corresponds to the type described by Remak in '55. 

 He maintained that "cell division proceeds from the centre 

 toward the periphery. It begins with the division of the nucleo- 

 lus, is continued by simple constriction and division of the nucleus 

 and is completed by division of the cell body and membrane" 

 (Wilson, :oo, p. 63). For a score of years after Remak's work 

 this w as supposed to be the prevalent if not universal type of cell 

 division. Then it gradually came to be recognized that karyoki- 

 nesis or mitosis was the usual form of nuclear division and that 

 amitosis was comparatively rare, in fact its very existence was 



