ON THE SPERMATOGENESIS OF THE SILK-WORM. I 2 Q 
It is certain that these round cells in the testicular follicle 
are genital cells. When the larva is about to be hatched, three 
depressions appear on the follicular wall. These gradually 
deepen until four cavities are formed. This is shown in 
fig. 5 /. Hand in hand with this change another depression 
appears on each of these testicular tubes as fig. 5 i shows, and 
in a testis of a larva four days old, there is seen a large cell 
in each of these secondary depressions of the follicle. This 
large cell is the origin of Verson 9 s cell found in the blind end 
of the testicular follicle. Similar structure is also found in a 
testis a little younger than this, but here a distinct membrane 
exists between the depression and the follicular space (fig. 6), 
so that the depression is produced by the swelling in of one of 
the cells of the follicular wall, and has no connection with 
the genital cells lying in the follicular space. It is therefore 
certain that Verson’s cell is derived from one of the follicular 
cells, and not from the genital cells. 
This depressed cell gradually loses its membrane and pro¬ 
duces amoeboid processes between the genital cells (fig. 11). It 
always has an elliptical nucleus which contains many chromatin 
granules (figs. 9, 10, 11, 12, 13, v), staining very deeply by such 
reagents as hæmatoxylin, carmine, and aniline dyes, and is 
connected with the follicular wall by a protoplasmic strand 
(fig. 8, p). It thus resembles very much the nucleus of follicular 
cells (fig. 6) which also contains many chromatin granules. 
Contrary to the assumption of Verson it has no nucleolus, nor 
any karyokinetic division to be found in it at any stage of its 
existence from the early beginning till the death of the moth. 
Verson’s cell is, as stated above, generally situated in the blind 
end of the testicular follicle, around which the youngest sexual 
cells are found (fig 7 v). Sometimes, however, it happens to be 
placed at one side of the follicle (fig. 10 v) where more developed 
genital cells are found, the most interesting thing about here is 
that the youngest genital cells are here also found at the blind 
end and not around Verson’s cell. As will be seen in fig. 10 the 
genital cells at the blind end of the follicle divide profusely as 
usual, although Verson’s cell is not present, and this shows that 
Verson’s cell has nothing to do with the formation of genital cells. 
The division of Vevson’s cell takes place, as Verson states, 
