524 
MONTGOMERY. 
[Vol. XV. 
io. Discharge of Nucleolar Substance from Resting Nuclei. 
Will (’84) holds that the larger nucleoli of the amphibian ger¬ 
minal vesicle pass out into the cytoplasm, and there become the 
yolk-nuclei ; and Scharff (’88) corroborates this view for the ova 
of Trigla , though it is opposed by Cunningham (’95). Macallum 
(’9i) concludes that in amphibian ova the peripheral nucleoli 
generate a substance which diffuses first in the nucleus and from 
there into the cytoplasm, and that this substance combines with 
the cytoplasm to form the yolk substance ; Jordan (’93) expresses 
a somewhat similar view in regard to the yolk formation of the 
newt. Henneguy (’93) assumes that the corpuscle of Balbiani 
in the ova of Vertebrata “ est tres probablement une partie de 
la tache germinative, ou une tache germinative entiere, qui sort 
de la vesicule [germinative] pour penetrer dans le vitellus,” and 
Mertens (’93) holds a similar view. And for egg cells of 
Tunicata , Floderus (’96) confirms Roule’s (’84) observations, 
that the “ intravitelline Korper ” are paranucleoli which have 
wandered into the cell body. Cf. also Bremer (’95a, b). 
Leydig (’88) finds that in ova of Geophilus , Stenobothrus, 
Rana, and Triton particles of nucleolar substance penetrate 
into the cytoplasm. Lukjanow (’88) concludes that in the case 
of the cells of the stomach mucosa of Salamandra , the nucleo¬ 
lus discharges a portion of its substance from the nucleus. 
Humphrey (’94), from observations on plant cells, maintains 
that in some cases portions of nucleolar substance may pass 
into the cytoplasm. 
Fol (’83a, b) concludes that the follicle cells of the ascidian 
egg arise as buds from the surface of the germinal vesicle, 
and that each of these buds contains a particle of nucleolar 
substance ; these conclusions are affirmed by t Roule (’83). 
Scharff (’88) supposes that the follicle cells of the ovum of 
Gadus are derived from nucleoli which have left the germinal 
vesicle, such nucleoli becoming the nuclei of the new cells. 
(Ogata ’83) studied human pancreas cells and finds that a 
nucleolus wanders out of the nucleus, becomes a “ Nebenkern,” 
and the latter finally changes into the nucleus of a new cell, a 
conclusion which is opposed by Platner (’89b). 
