290 
MONTGOMERY. 
[VOL. XV. 
1883 . 
Balbiani (’83) renewed his observations on the egg of Geophilus 
longicornis , making several emendations. In very young eggs 
there are two or numerous nucleoli, in larger eggs only one large 
one, containing one or several vacuoles. In his previous paper 
referred to, he assumed that the double tubular structure in 
these eggs served for the purpose of an intraovular circulation; 
but in the present paper he offers another explanation: that 
the double tubular structure later develops into a knotted cord, 
the distal portion of which then divides into irregular frag¬ 
ments, which become scattered through the yolk ; and then each 
of these fragments, with the exception of one which becomes 
the “ noyau vitellin,” differentiates into cytoplasm, nuclear and 
nucleolar substance, and then represents a cell of the follicular 
epithelium. 
Van Bemmelin (’83) states of the eggs of Brachiopoda : “ Sie 
haben meist zwei Kernkorperchen, die enganliegend und stark 
lichtbrechend sind. Ausser diesen nimmt man oft noch mehrere 
lichtbrechende Kiigelchen in dem gefarbten Inhalte der Eikerne 
wahr. Von Boraxkarmin werden sowohl diese Korperchen als 
die Nucleoli stark gefarbt.” (Certain of his figures show one 
of the nucleoli imbedded in another.) 
Van Beneden (’83), ovum of Ascaris megalocephala: there is 
a single “ corpuscle germinatif,” which contains all the chro¬ 
matin of the nucleus, and is contained within a special portion 
of the nucleus termed the “ prothyalosome ”; from one to three 
“ pseudonucleoles” also occur in the nucleus, but they play no 
important part in the maturation of the egg. 
Fol (’83a), egg of Ciona intestinalis: there is here one large, 
very refractive nucleolus containing a number of vacuoles 
which he believes are artefacts, since they cannot be found in 
the living egg, though their appearance after the action of 
reagents would show that the substance of the nucleolus is 
chemically not homogeneous. The nucleolus consists of a more 
refractive cortical substance, and of a less refractive, clearer 
medullary portion ; in the latter, the vacuoles are produced. 
Fol maintains that the follicle cells arise by budding from the 
