GERM CELLS IN THE ARTHROPODA 149 
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posterior ‘‘ massa monembrionale,”’ which produces 
the so-called asexual larve. These lack reproductive, 
respiratory, circulatory, and excretory systems. They 
are supposed to develop from cell masses which do 
not contain descendants of the cell with “ nucleolar” 
material, and to serve the purpose of tearing apart 
the organs of the host, thus making it available as 
food for the normal larve. The ‘‘ massa monem- 
brionale,”’ according to this view, consists entirely of 
somatic cells, whereas the “massa germinigera”’ 
possesses both somatic and germ cells. Doubts 
have been expressed regarding the development of 
the asexual larvee, and Silvestri’s results need con- 
firmation. There seems to be no doubt that the 
“nucleolo” is a keimbahn-determinant in both 
monembryonic and polyembryonic HyMENoPTERA, 
but its identification as the nucleolus from the odcyte 
nucleus did not seem to the writer to be well estab- 
lished. Its history was, therefore, studied by the 
writer (Hegner, 19145) during the growth period of 
the eggs, with the following results. 
My material consisted of a brood of females 
belonging to the polyembryonic species Copidosoma 
gelechie. Asin most other insects, the two ovaries of 
Copidosoma consist of rows of odcytes in various 
stages of growth — the oldest and largest near the 
posterior end, and the youngest and smallest at the 
opposite pole. Before the ojgonia enter the growth 
period (Fig. 46, A, 0) each becomes surrounded by 
a follicular epithelium (fe) and is provided with a 
group of nurse cells (nc) which likewise are enclosed 
