PHENOMENA ACCOMPANYING FERTILIZATION 



299 



than 100), but described 6 chromosomes in Stylonychia pustulata. 

 Stevens (1910) described 4 chromosomes in Boveria subcylindrica, 

 but gave no details of their formation or reduction. Enriques 

 (1908), confirmed by MacDougall (1925) found 4 in Chilodon 





Fig. 149. 



-Chilodon uncinatus. Third division and interchange of nuclei of diploid 

 (A) and tetraploid (B) stock. (After MacDougall.) 



uncinatus; Popoff (1908) 16 in Carchesium polypinum; Enriques 

 (1907) the same number in Opercularia coarctata, and Collin (1909) 

 G chromosomes in Anoplophrya branchiarum. 



Hamburger (1904) is a bit hazy in her account of the origin of 



