130 ON THE SPERMATOGENESIS OF THE SILK-WORM. 
amitotically. Its nucleus becomes constricted into two or more 
portions producing from one to many small nuclei on the side of 
the large one. This mode of division is not to be seen in the 
first larval stages, but commencing generally at the end of it, 
gradually increasing to the imaginai stage (Figs. 6, 11, g, 12, 13 v); 
but the genital elements are seen to increase in number from the 
first larval stages, where no division of Verson’s cell is found. 
In a testis of an imago after copulation, I have also met with 
Verson’s cell, but now it does not stain so well by the reagents 
above described as in earlier stages (fig. 13). At this stage, there 
is seen a number of cells close to Verson’s cell, probably corres¬ 
ponding with the cells formed by the above described amitotic 
division of it. These cells also take no stains and contain large 
vacuoles, showing thus the process of degeneration. 
From all this we arrive at the conclusion that Verson’s cell 
is not a genital cell as Verson states, but it is a supporting cell 
connecting all the younger genital elements with the wall of the 
testicular follicle and probably nourishing them. This confirms 
the assumption of Ziegler and vom Rath (46), who says that “ es 
erscheint eine Deutung zulässig, welche die Befunde von Verson 
mit denen von vom Rath in Uebereinstimmung bringen könnte, 
nämlich die Auffassung, dass die kleinen Zellen nicht die Ab¬ 
kömmlinge, sondern sozusagen die Geschwister der grossen Zelle 
(' Verson’s cell) sind und dass sie durch successive mitotische 
Theilung die zahlreichen Samenbildungszellen erzeugen, währ¬ 
end der Kern der grossen Zelle, welche den Character einer 
Rand- oder Stütz-zelle hat, mehrfach sich amitotisch theilt.” 
Verson’s cell may therefore be safely assumed to be a 
supporting cell of the testicular follicle, and is also to be seen 
in the blind end of an egg tube as is shown in fig. 14 and in quite 
young stages, it is very difficult to distinguish the male and 
the female elements except by the external shape of the follicle 
as already described. 
(1) The cells which divide amitotically in the genital follicles of the silk-worm 
do not belong to the cycle of sexual cells as above described and this confirms the 
opinion of vom Rath (29, II) who says that “ Dem Mitosen gegenüber haben die 
Amitosen durchweg einen mehr oder weniger deutlich erkennbaren degenerativen 
Character. Die Mitose hat sich keineswegs aus der Amitose entwickelt, so dass die 
letztere den ursprünglicheren Theilungsmodus darstellte.” 
dMilü 
