CYTOPLASMIC INCLUSIONS OF THE GERM-CELLS. 559 
rations show that in this region one soon finds filaments of a 
variable size. These rods or filaments are known as “ corps 
intracytoplasmiques.” The latter seem to be either solid rods 
or formed of moniliform structures placed in a series. 
Ancel thinks that the young spermatocytes do not contain 
a Nebenkern. Their cytoplasm is filled with short, colourable 
filaments. The Nebenkern, which appears at the expense of 
the cytoplasmic filaments, augments in size as these filaments 
disappear. At the beginning of mitosis the Nebenkern frag- 
ments and disappears. Ancel denies that the Nebenkern is 
related either to the nucleus, the spindle, or the “ sphere 
attractive,” and gives it as his opinion that this curious body 
“ne represente, a notre avis qu'une phase de revolution des 
formations iutracytoplasmiques.” 
Elsewhere Ancel states : “ Le Nebenkern ne jouerait done 
aucun role dans les cellules ; il ne serait que le produit de 
transformation des filaments cytoplasmiques differences aux- 
quels serait devolue une fonction speciale.” 
R. Demoll ( 3 ) describes the fact that these are prophases 
of the heterotypic division in the female, which was over- 
looked by Ancel. He describes the Nebenkern somewhat 
better than Ancel or previous authors and considers that this 
body determines the sex of the differentiating cell. 
Writing of the “ Bukettstadium in beiden Keimzellen,” 
Demoll gives the following : “ Mit dem Ausstofen des Neben- 
kernes wird sowohl die Wachstumsgeschwindigkeit als aucb 
die Genese der chromatischen Substanz fur die beiden Arten 
von Keimzellen eine spezifische. Oder : Der Nebenkern 
bedingett erst die geschlecht liche Differenzierung der bis zum 
Bukettstadium indifferenten Keimzellen.” In the discussion 
it will be shown that for a number of good reasons DemolTs 
sex determination hypothesis cannot be accepted (page 40). 
Iw. Buresch ( 4 ) has also attacked the problem, but his 
paper contains little of interest from the point of view of the 
means whereby sex is determined. His work is not a great 
advance on that of Ancel, written many years before, while 
he has failed to study any cytoplasmic inclusions. Buresch 
