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 (Faure- 

 Fremiet, 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 Peripatus. 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." 



Faure-Fremiet 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 



