GENERAL ANATOMY. 



8l 



the peculiar hereditary substance (as observations upon 

 fertilization seem to show), while the achromatin plays a 

 role in cell multiplication. 



FIG. zo. Cell division according to Rabl. (Skin of Salatnandra maculosa.) 



Cell Budding. - - Cell multiplication is undoubtedly 

 brought about chiefly by division, and usually indeed by 

 binary division. On the surface of the cell there appears 

 a circular furrow which, deepening, cuts the cell into two 

 equal parts (Fig. 20). 

 (Division in the narrower 

 sense.) Less frequently ^^^L^^l^^/^i 

 cell budding (gemma- 

 tion) takes place, in the 

 course of which a large 

 mother-cell cuts off from 

 itself one or more daugh- 

 ter-cells (Fig. 21). For 

 a long time there was a 

 controversy concerning 

 the behavior of t 

 cleus ; some investigators nucleus - 

 affirmed that the nucleus disappeared previous to the 

 division, and that in each daughter-cell a nucleus was 

 formed anew ; other investigators believed that the nucleus 

 was cut in two analogously to the cell. Although the first- 



rm FIG. 2I - Podophrya gemmipara with buds, a. 

 constricting off and becoming swarmers (by, N, 



