704 
J. P. Munson 
Dotterkern der Hymenopteren usw. bildet sieh in der Kähe des Keim- 
bläschens, unter dem Einflüsse desselben, aber nicht aus ih m.” 
The latter view corresponds to that expressed by Munson (61) who 
found in the egg of Limulus that the granulär zone around the germmal 
vesicle was a temporary effect due to the action of karyolymph on food 
material, the karyolymph being considered as a digestive fluid. He 
found that in the spermatocytes of the butterfly (Munson [63]), the 
nutrition of the cell is interfered with when the nucleus falls to secrete 
the karyolymph. He also found a clear zone around the germinal vesicle 
whicli he interpreted as evidenee of the entrance of the clear karyo- 
lymph into the eytoplasm since little remained in the germinal vesicle 
when this extrusion had taken place. 
Munson (65), however, distinguishes between this granulär yolk 
nucleus and what he calls the vitelliue body, the latter being interpreted 
by him as the centrosome of the dividing oogonia. His researches and 
many later ones yet to be c-ited render this Interpretation very probable. 
According to Holländer (36) there are two different elements found 
in the egg of birds and mammals : first elements of nuclear origin ; sec-ond 
an attrac-tion sphere described as a Condensed mass outside of the germinal 
vesicle — the eouehe palleale of van Bambeke and the couche vitello- 
gene of van der Stricht in whicli one can make out a central body. 
Prenant (73) seems to liave had a suspicion of the same fact ; for 
in speaking of the body of Balbiani in arachnids, which Balbiani called 
the “vesicule embryogene”, Prenant says: “Since then some bodies 
undoubtedly analogous to this body liave been found in various eggs — 
vitelline nucleus of 0. Schultze (amphibia); sphere attractive of E. van 
Beneden; archoplasmic sphere and centrosome of Boveri; and c-orpuscide g 
polaire of Vialleton. Prenant says undoubtedly they are analogous 
bodies.” 
The importance of this question is # seen in the following Statement 
by Wilson (95), which also reveals the attitude of that distinguished writer 
on this problem: Speaking of the vitelline body of Munson, he says: 
“Munson’s observations show that this body first appears in the very 
young ova as a crescent applied to the nucleus precisely as in Molgula 
or Inonbricus, but containing one or more central granules . . . and if it 
be a true attraction sphere in the one case, we must probably so regard 
it in all.” Wilson failing to offer any reason for this supposed necessity 
introduces the problem of a de novo origin of the centrosome — a theory 
which is based entirely on negative evidenee. Munson (61) has clearly 
shown that the crescent shaped body in young ova of Limulus is the 
