49 



the female piurent does not fuse completely, and that the 

 nucleoli of different origin reiaain distinct for some time 

 after nuclear fusion. The "beliavior of the chroi.iosomes in 

 the eeirly di:?isions of the fusion nucleus was not observed, 

 though it ',/ould "be of considerable interest to know v/hether 

 two distinct groups of cliromosomes are formed at this 

 stage. 



The fusion nucleus divides once in the auxiliary cell, 

 and the two nuclei come to lie in the opposite ends of the 

 now some-vvhat elongated cell (fig, 89), Between them lies 

 the greatly enlarged central nucleus originally present. 

 Each of the nuclei resulting from the division of the fu- 

 sion nucleus usually shows the characteristic double nu- 

 cleolus. The aiuciliary cell nov.- divides^ ©ne daugter 

 cell containing the enlarged central nucleus and a single 

 fusion nucleus, and the other containiTig^only a fusion nu- 

 cleus (fig. 90) . The latter may be called the placental 

 cell* from it the sporogenous lobes usually arise. Figtire 

 92 shows clearly that sporogenous lobes may also be formed 

 from the auxiliary cell after tlie placental cell lias been 

 found; the nuclei entering these lobes are derived from 

 the fusion nucleus. Very similar behavior ha.s been observ- 

 ed by HASSEIICAI.IP ('02) in the auxiliary cells of Thuretella 



