686 
scribed by Dr. Frevp. In the objects I examined, they appear to 
correspond to a type of body I have already described as dietyo- 
somes in the spermatogenesis of BRAncHIPuUs. (The account of these 
bodies is contained in an unpublished paper in the hands of the 
Editors of the Quart. Journ. of Microsc. p. Sci.) 
A little later in the development we find the spermatid nucleus 
(fig. 2) becoming less chromatic, but a number of minute chromatic 
particles (fig. 2c) are to be seen, some diffused throughout the cell, 
some in actual transit through the nuclear confines. These chromatic 
particles become rapidly collected together into a granular extra-nuclear 
mass (fig. 3c) which corresponds to Hermanns chromatic body, 
and I shall speak of it as such. 
Comparison of the spermatids, while the little particles are sepa- 
rating and during the formation of the chromatic body, will show that 
an inverse ratio exists to some extent, between the stainability of this 
structure and that of the nucleus, the latter gradually becoming under 
the action of reagents almost colourless. For some purpose (presumably 
adaptive) the chromatin is transported by small granules into the cell 
body and there massed pending future changes. 
Concomitantly with these alterations in the nucleus itself, the Neben- 
kern (Archoplasm) undergoes a curious metamorphosis, numbers of 
clear vesicles appearing in its substance each containing a dark 
spherical particle. Eventually all the vesicles and particles coalesce 
so that there results one clear space and one dark spherical particle 
(fig. 3e) (see Benpa, Verhandl. Anat. Gesell., Bd. VII, 1892, p. 
175—179) which invariably lie between the undifferentiated remains of 
the Nebenkern (a) and the nucleus itself. These Nebenkern remains 
(fig. 1a) which I shall call collectively the Residual Nebenkern 
are thus detatched from the nucleus and wander into the cell body 
The vesicle disappears as such, but the dark sphere (fig. 3e) becomes 
continually more closely applied to the nuclear membrane, until it is 
only discernable as a little wart on the circumference. 
At this stage the centrosomes grow very prominent; and the nucleus 
having become pointed in the direction of the lumen of the tubule, an 
excersively small body is apparently extruded; from this body there 
passes in the same direction a faint refractive radius ascross the cell, 
the first appearence of the tail. 
The Residual Nebenkern and the chromatic body arrange themselves 
definitely with respect to this axis formed by the growing tail, the 
