SPERMIOGENESIS OF HELIX ARBUSTORUM. 
305 
frequently Heidenhain’s iron hematoxylin, either used alone, or preceded 
by Bordeaux B or 025 % anilin blue. Benda’s crystal violet and sodium- 
sulphalizarinate-toluidin blue have also been excellent, particularly in 
staining the centrosome. I have also used Biondi -Ehrlich’s triacid, 
saffranin, Delafield’s and Böhmer’s hematoxylins. 
1. The spermatogonia. 
The spermatogonia of Helix, as shown by Ancel (2), develop 
from the «large germ-cells». These latter in the genital gland of the 
adult Helix are no more to be found. Plate VIL, Eig. 1. shows the 
cross section of a young follicle of adult Helix arbustorum filled with 
ovoidal or spherical cell nuclei. Their chromatin consists either of sepa¬ 
rated clots or of small chromomeres which are connected by delicate 
chromatin threads. The chromomeres form in places larger masses. 
The nuclei have no nucleoli, and are arranged in the young latest 
developed follicles in one layer along the wall of the follicle, and they 
fill only later its whole lumen. The nuclei are imbedded in a delicate 
alveolar ground substance, therefore such a follicle is really a large 
syncytium. 
These nuclei represent the spermatogonia. There are to be found 
spread among them some peculiar cells which are originally very similar 
to the spermatogonia, but are later very easily distinguishable by 
their very large nucleus filled with rough chromatin clumps, and by 
their small amount of cytoplasm. These cells are the base-cells which 
later become the nurse-cells of the developing spermatozoa and are 
equivalent to the SERTOLi-cells of the testes of Mammals. 
Spermatogonia like those described above are also to be found 
along the walls of those follicles in which the spermatozoa are already 
developing. The nuclei in these follicles are sometimes crowded so much 
that their outlines become indefinable, and can scarcely be distinguished. 
They have very often the structure shown on Fig. 2., PI. VII, when 
the chromatin is divided into some clumps irregular in shape, 
connected with one another by delicate threads. The clumps are 
sometimes fairly far from one another (PI. VIL, Fig. 2.), at other times 
closely together, and nearly coalesced. The outlines of the cells cannot 
be distinguished, because they are imbedded in a common ground 
plasm, as above. In Paludina , as is shown by Meves (72) the walls 
of the follicles are covered by giant cells, the base-cells, an the sperma¬ 
togonia are imbedded in their cytoplasm. So it is, according to the 
same author, in Helix. But this latter statement is undoubtedly erro- 
20 
Annales Musei Naiionalis Hung arici VIH. 
