SPERMATOGENESIS OF HUSCHISTUS 763 
of the stain. Both may be readily distinguished in life during 
the growth period. 
In the spermatocytes they are almost invariably single, rarely 
double, in number, and appear first as flattened discs upon the 
inner surface of the nuclear membrane (figs. 8, 14). Generally 
they are not recognizable at such early stages, usually not until 
about the commencement of the leptotene condition. They 
maintain this peripheral position, increasing in size until well 
into the strepsinema stage (figs. 26, 29-33, 35, 37-39, 42, 43, 
45-47, 50-52)." It is to be noticed that their exact position 
upon the nuclear membrane is quite variable, save that they are 
rarely near the chromatin plate and never in contact with the 
idiochromosomes. They later change this position to become 
free within the nuclear cavity (figs. 53 to 68). In the prophases 
of the first maturation division they become smaller and gradually 
disappear without a trace before the autosomes have taken their 
definitive forms (figs. 69 to 73 and 75). No plasmosomes seem 
to be produced during the histogenesis of the sperm. 
During the growth period there are certain constant relations of 
the plasmosomes to the autosomes. As long as the plasmosomes 
remain against the nuclear membrane they are in contact with 
radiating strands of the chromatin (autosomes), as shown in 
figs. 14, 22, 26, 29-33, 37-39, and most frequently the condition 
is that of the chromatin ending with a broadened plate upon the 
surface of the plasmosome (figs. 22, 29, 32, 37, 39); thus the plas- 
mosome frequently appears much darker than it really is by reason 
of the covering of chromatin. Usually not more than two 
autosomes make this connection, frequently only one, and this 
connection is the more noticeable because, during these stages, 
autosomes haveno other regular peripheral attachment except with 
the chromatin plate that lies next the idiozome. When the plas- 
mosome has grown much larger it loses its connection with auto- 
somes (figs. 42 to 52); and after this contact has become broken 
the plasmosome continues to increase in volume, so that its growth 
11 Jn the nuclei of figs. 47 and 50 they appear to lie free within the nuclear 
cavity, but this is simply-because they are not seen in profile. 
