160 RAYMOND BINFORD 
7. The capsule arises in the cytoplasm as a clear vacuole which 
may be stained with Lichtgriin. Its content is gradually changed 
to have a greater affinity for chromatic stains. 
8. From a granule on the proximal side of the capsule the 
central body develops into the capsule. At the distal end of 
this body a vesicle arises, which is changed into the inner tubule. 
9. The mitochondrial substance is segregated from the cyto- 
plasm and deposited as a ring between the nucleus and the 
capsule. 
Some of the theoretical questions connected with the develop- 
ment and structure of the spermatozoa of the decapods will be 
taken up at the end of this article. At this point I wish to say 
that the above description is in agreement with the principal 
observations made by Grobben (’78), Gilson (’86), Sabatier (93), 
Brandes (’97) and Koltzoff (06). These authors have all seen 
the same general structures and transformations. They all de- 
scribe a nucleus which, during development, is modified in its 
staining reactions, reduced in size and often flattened or other- 
wise changed in its shape. They do not disagree as to which 
part of the cell is the nucleus. They likewise describe a vesicle 
which arises in the cytoplasm either against the nucleus or close 
to it, and they mention the substance of cytoplasmic origin which 
appears between the nucleus and the vesicle. Most of them see 
a structure like the central body and describe the inner tubule. 
There are many variations in the detail of the development of 
these last two structures, and different species seem to differ 
widely in this respect. There is much disagreement concerning 
the destiny of the nucleus and the origin and nature of the sub- 
stance in the capsule. These points of disagreement do not 
however affect the statements I have made concerning the struc- 
ture of the mature sperm. It is with this structure that we 
have to do in the further course of the present investigation. 
