PROCESS OF FERTILIZATION IN THE CRAB 17 
the origin of the capsule, I am unable to distinguish any granule 
which can with any certainty be identified with the centrosome. 
I shall call the structure developed from this granule, the ‘cen- 
tral body.’ I am unable to follow the development of two dis- 
tinct granules although two could sometimes be clearly distin- 
guished as shown in figure 44. Probably only the outer one is 
concerned in the development which is here presented. 
This outer granule elongates (fig. 47) and becomes tubular 
(figs. 50 to 56). There soon appears at the outer end a vesicle 
which increases in size as the central body elongates. While the 
vesicle is still small there appears in its outer wall a flattened 
granule which is usually seen to be connected with the end of 
the central body by means of a fine strand as though it might 
have been derived from this body. As the central body increases 
in length and the vesicle enlarges, its outer wall approximates 
the outer wall of the capsule. The deeply staining substance in 
the outer wall of the vesicle now becomes connected with the 
wall of the capsule (figs. 56 to 58). A second vesicle now forms 
(fig. 59). These two vesicles become transformed into a tubule 
containing the central body. This tubule will hereafter be 
spoken of as the ‘inner tubule.’ At its outer end a ring of darkly 
staining substance is found (fig. 60). This seems to have been 
derived from the central body. At least a study of figures 54 
to 60 may well suggest such an interpretation. The central body 
finally becomes reduced in diameter and appears to be a solid 
rod. It is not stained by thionin nor by safranin, but is readily 
stained with iron-hematoxylin. The inner tubule is stained green 
with safranin counter-stained with Lichtgriin; blue with thionin 
counter-stained with eosin; and black with iron-hematoxylin. 
During this whole period the content of the capsule shows an 
increasing affinity for chromatin stains. It is colored brown with 
iron-hematoxylin. In some series a sort of ring-shaped cloud 
appears in the capsular contents. At first it is near the outer 
wall but gradually it contracts towards the vesicle at the end 
of the central body and finally settles in the wall of the tubule 
when that structure takes its final form. With Delafield’s hema- 
toxylin the contents of the capsule is readily stained, and with 
