698 
J. P. Munson 
These observations eorrespond very closely to those of Munson (61). 
He found eggs of Limulus crowded with real nuelei, giving all the staining 
reactions of chromatin. He also raises the question whether these nuelei 
are due to phagocytes or whether they residt from fragmentation of the 
germinal vesicle which is no longer to be found in such eggs. At first the 
yolk containing these nuelei appears normal. Later the yolk granules 
disappear, and the nuelei lie imbedded in the protoplasm, but cell bound- 
aries separating the nuelei are not to be seen. The entire egg is finally 
absorbed or transformed into cells resembling those lining the walls of 
the ovarian tube. 
Munson (63) has also seen degenerating spermatogonia in the butterfly. 
Ko cells app.ear within the spermatogonia or spermatocytes, but they 
crumble to pieees, not from fatty degeneration as Schneider assumes, 
but from starvation. In a later paper Munson (64) explains the degene- 
ration of spermatogonia as being due to an abnormal condition of the 
nuclear ehromatin. It was found that those degenerating cells do not 
secrete the karyolymph in the chromatin which according to hinr is 
necessary to digestion; and c-onsequently, as he says, the cell dies from 
starvation due to indigestion. According to this view leucocytes may 
enter the cell after it is diseased, and remove it as phagocytes do other 
foreign bodies. In the c-ase of the spermatogonia, they simply crumble 
to pieees and furnish a “Protoplasmalösung”, as Weismann c-alled it, 
serving as food for other cells. 
Extrusion of Nuclear Material. 
Many observers have noticed that the germinal vesicle is often sur- 
rounded by a ring, which is either lighter or more granulär than the rest 
of the cytoplasm. And this, again, raises the question, first as to the origin 
of yolk; and second, as to the relation of this inner ring to the yolk nucleus. 
As early as 1863, Pflüger (71) distinguished an inner and an outer zone 
of yolk in mammalian ova, and the clear zone seen by 0. Schultze (83) 
seems to eorrespond with what Brass (15) called the “Nährplasmaschicht”. 
Schultze (83) figures four eggs of frog with a zone around the germinal 
vesicle, and a yolk nucleus between the inner and the outer zone, sug- 
gesting the observations of Bambeke (7) and of Munson. He says : 
“The membrane of the germinal vesicle was irregulär, and around it, 
a clear zone had arisen.” The granules of the yolk nucleus began to sep- 
arate first at the periphery of the egg. Thereupon granules separated 
from the yolk nucleus . . . these spread in a dark granulär zone around 
the germinal vesicle . . . The clear zone mav be present in eggs that 
