444 
George Arnold 
origin. The archoplasm (a) lies to one siele of it. Eventually when 
the ruetaphase sets in, this vacuole breaks down (Fig. 39) and tke chro- 
matic body once more takes up a position in the cytoplasm some 
distauce from the nucleus. 
It is difficult to understand the object of the formation of this 
vacuole, but it suggests a precocious attempt at the formation of an 
archoplaswic vesicle. The centrosomes at the 2nd. meiotic divisiou 
are very difficult to distinguish; in Fig. 38 there is a small body 
lyiug above tbe nucleus with faint radiations arising from it. Possibly 
this represents a centrosome. 
The chromosomes of the 2nd. meiotic division are V shaped rods 
(Fig. 40) showing, in some instauces, a very clear longitudinal split, 
the plane of division. 
The subsequent changes in the nucleus of the spermatid call for 
no special notice. 
Owing to the small size of the cells, many of the details in the 
formation of the cephalic cap have not been made out, but what can 
be seen shows that the transformations whicli lead up to it do not 
diverge from those whicli have been described in many otlier animals. 
The chromatic body before mentioned is seen in all the cells 
containing spindle figures (Fig. 40 c). Whether it divides or not, or 
dissolves in the cytyplasm, has not been ascertained. However, 
immediately after the Separation of the daughter cells, and when a 
new nuolear membraue has appeared, a chromatic body is again seen 
in each daughter cell (Fig. 41, c). 
But here it is not surrounded by a clear area, it lies close to 
the archoplasm, which is derived from the remains of the spindle 
(Fig. 42). A vacuole appears in the archoplasm, which grows larger 
and larger, while the chromatin aggregations in the nucleus gradually 
dissolve in the nuclear sap (Figs. 43 and 44). 
When this vacuole is about one-third of the size of the nucleus, 
a large deeplv (basic) staining granule appears in it close to its 
periphery and away from the nucleus. This is the archosome (= acro- 
some, von Lenhossek). 
The transition between the stage shown in Figs. 44 and 45 is 
probably very rapid. At any rate, stages intermediate between these 
two have not been seen. 
When the archoplasmic vesicle has arrived at the stage shown 
in Fig. 45, the chromatic body (c) has broken up into minute granules, 
which become arranged in an even mauner on the outer surface of 
