134 GERM-CELL CYCLE IN ANIMALS 
the formation of chromosomes and amphiaster” 
(p. 437) and concludes from a review of the literature 
up to the year 1900 “‘that in the vast majority of 
cases amitosis is a secondary process which does not 
fall in the generative series of cell-divisions”’ (p. 119). 
During the past ten years interest in direct nuclear 
division has been maintained principally because of 
the claims of certain investigators that germ cells 
may multiply in this way and still give rise to func- 
tional eggs or spermatozoa. 
During amitosis the chromatin remains scattered 
within the nucleus and does not form a spireme 
nor chromosomes, and therefore its individual ele- 
ments, the chromatin granules, do not divide. As 
a result of this mass-division there can be no accurate 
segregation of chromatin granules in the daughter 
nuclei as is demanded by the theory that the nucleus, 
and particularly the chromatin, contains the de- 
terminers of hereditary characteristics. Further- 
more, nuclear division without the formation of 
chromosomes obviously condemns the hypothesis 
of the genetic continuity of the chromosomes, and 
hence seriously interferes with current ideas regard- 
ing the significance of the accessory chromosomes in 
the determination of sex. Among the animals in 
whose germ cells amitosis has been reported are cer- 
tain AMPHIBIA, ccelenterates, cestodes, and insects. 
Ampuisia. Vom Rath (1891, 1893), Meves (1891, 
1895), and McGregor (1899) have recorded amitosis 
in the germ cells of Ampuipra. Meves claims that 
the spermatogonia of Salamandra divide amitotically 
