CHROMOSOMES AND MITOCHONDRIA 285 
78, D) and Wilke (1912) in the spermatocytes 
of Hydrometra or en masse, as in the spermatogenesis 
of Euschistus (Fig. 78, A-B), thus undergoing a sort 
of paramitosis (Montgomery, 1911) and Notonecta 
(Browne, 1913). In the former cases each daughter 
cell is supposed to receive one-half of each granule; 
in the latter the distribution is largely by chance, 
but apparently equal (Cowdry, 1914). According 
to certain observers the centrosomes exert an in- 
fluence upon the mitochondria as indicated by the 
aggregation of these bodies around the asters (Fauré- 
Frémiet, 1910; Meves, 1914); but others have been 
unable to find any confirmatory evidence in their 
material (Montgomery, 1911). Duesberg (1908) 
has pointed out that since there is no rest period 
between the two maturation divisions there must be 
a quantitative reduction of plastosomes in the sper- 
matids; a quartering of the mitochondria could 
not, however, be observed by Montgomery (1912) 
in Pertpatus. Montgomery (1911) has suggested 
that the relative amount of the mitochondrial sub- 
stance received “‘might determine the sex-prepon- 
derance character of the sperm, a matter unfor- 
tunately very difficult to test.” 
Fauré-Frémiet recognizes four types of mitochon- 
drial distribution in the germ cells: (1) filaments or 
masses that do not undergo profound morphological 
changes (Fig. 80); (2) one or more masses which 
transform into a definite morphological element, 
the Nebenkern; (3) masses which only partially 
change into a Nebenkern or yolk nucleus; (4) bodies 
