GERM CELLS IN THE ARTHROPODA 139 
I have studied my preparations of chrysomelid 
beetles carefully with the aim of detecting amitotic 
division and have observed what appears to be direct 
nuclear division among the nurse cells, but could not 
demonstrate with certainty this kind of division 
among the oégonia, or spermatogonia. Three stages 
inthedirect division of nurse cell nuclei in Leptinotarsa 
decemlineata are shown in Fig. 8, a-c. Odgonia 
and spermatogonia, however, do not exhibit such 
clearly defined stages and after examining my prep- 
arations and several slides kindly sent me by Doctor 
Wieman I am forced to conclude that amitosis has 
not been demonstrated. It is true that frequently 
dumb-bell shaped nucleoli occur in certain of the 
nuclei and frequently two nucleoli are present at 
opposite ends. Also two nuclei may be surrounded 
by a single cell wall, but no stages were present which 
could not be attributed as well or better to mitotic 
phenomena. 
Conctusion. From the evidence at present 
available we must conclude that amitotic division 
of the germ cells has not been demonstrated, and 
that not until such a process is actually observed 
in living cells will any other conclusion be possible. 
There are still two questions regarding the germ- 
cell cycle in beetles that we shall attempt to answer ; 
(1) Does a chromatin-diminution process occur 
such as has been described in JMiastor and Ascaris? 
and (2) Is the segregation of the germ cells controlled 
by the nuclei or by the cytoplasm ? 
The fact that part of each chromosome is cast out 
