GERM CELLS OF HERMAPHRODITES 203 
in the autosomes. In Helix the odgonia and sperma- 
togonia arise from cells that are similar in size and 
constitution (Fig. 60, A). When the germ-cell 
nuclei reach the bouquet stage, a Nebenkern appears 
near the side against which the chromatin threads 
Fic. 60.— Helix pomatia. Stages in the differentiation of male and 
female sex cells. A. Young odcyte. B. Later stage of odcyte 
showing faint Nebenkern. C. Young spermatocyte. D. Later 
stage of spermatocyte showing well-marked Nebenkern. JZ. Still 
later stage of spermatocyte containing Nebenkern consisting of 
banana-shaped rods. (From Demoll, 1912.) 
become packed. This Nebenkern is probably a 
product of the nucleus; it appears in the female 
cell only as a slightly darker area of cytoplasm (Fig. 
60, B) but in the male cell is more dense (D), later 
consisting of a number of darkly staining banana- 
shaped pieces (£). With the appearance of the 
Nebenkern the specific growth of the female cells 
