330 
Dì L. SOÓS 
Helix arbustorum has another abnormal chromosome, or chromo¬ 
some-like body, which gets at the beginning of the metaphase of the 
primary spermatocytes out of the spindle, and then lies in the cyto¬ 
plasm (PL IX., Figs. 6., 8.). I have already mentioned this body. I am of 
the opinion that this body is identical with the nucleolus. This sugges¬ 
tion cannot be supported by immediate observation, because the nucleo¬ 
lus, as regards its constitution and coloration, at the end of the prophase 
does not differ from the ordinary chromosomes. There is, however, an 
important circumstance supporting this suggestion. 
We have already seen that the nucleolus increases till the end of 
the prophase into a very large body, and entirely disappears in the 
young secondary spermatocytes, therefore it must disappear in some 
phase of the division. There is no trace of its having been dissolved, 
consequently its disappearance can only be explained by its being cast 
out into the cytoplasm. The suggestion that the body thrown out 
might be identical with a true chromosome contradicts all our empiri¬ 
cal knowledge and theoretical deductions. The casting out of the nucleo¬ 
lus, however, has already been observed in several cases. Buchner (18a) 
observed the phenomenon in Gryllus ; Duesberg (22) is of the opinion 
that the chromatoid body of the spermatocytes of the rat is identical 
with the nucleolus cast out into the cytoplasm, and I even conclude 
from the figures of Arnold (3, PL X., Figs. 18 and 21) that in sper¬ 
matogenesis of Hydrophilus piceus a similar process takes place, though 
Arnold interpreted these figures in a different way. 
I consider the casting out of the nucleolus from the nucleus as 
the ending of the process which has the purpose of freeing the nucleus 
from its superfluous chromatin, and thus assist the cell through the 
depression. When I discussed the phenomena of the depression I men¬ 
tioned that that explanation had a difficulty, viz., it is difficult to under¬ 
stand the great capacity of absorbing chromidia of the small cytoplasm 
of the pachytene cell. It is a very important phenomenon that the 
nucleolus begins to increase enormously even when the cell is in the 
pachytene stage, and it takes up more and more chromatin, i. e. it 
then transforms itself into a chromatin nucleolus. I am of the opinion 
that this process, the binding of the superfluous chromatin, introduces 
the balancing of the depression. Upon this hypothesis the difficulties 
of the explanation mentioned certainly diminish considerably. 
6. The development of the spermatozoa. 
The isolated young spermatids are spherical in shape (PL XL, 
Figs. 1., 3.), those in groups, however, are polygonal (PL X., Fig. 9., 
