3 2 6 
MONTGOMERY. 
[Vol. XV. 
nucleolus breaks into a number of nucleoli of various sizes. 
After the copulation and encysting the nucleoli fuse together 
and gradually disappear (but I am unable to determine from 
his description whether the substance of the chromosomes is 
derived from the nucleoli). Shortly after the nuclei themselves 
copulate, the nucleoli reappear in them. In Clepsidrina blat- 
tarum there is a single primitive nucleolus, formed as in 
the preceding species ; later there are numerous smaller 
nucleoli, which have probably arisen by division from the 
primitive nucleolus. 
1892. 
Bannwarth (’ 92 ) figures a division of the nucleolus in leuco¬ 
cytes from the spleen of the cat. 
Born (’92) finds that in the Amphibian egg, in opposition 
to the observations of O. Schultze (’87), the chromatic “ Faden- 
knauel ” has no origin in the nucleoli, but is directly derived 
from the chromatin network of the “Urei.” 
Brauer (’92) made observations on the maturation and fecun¬ 
dation of the egg of Branchipus. Each germinal vesicle from 
the “ Wachsthumszone ” of the ovary has one large, slightly 
staining nucleolus, and near it a much smaller, deeply staining 
one. Each “ Nahrzelle,” however, contains numerous nucleoli, 
and its nuclear sap also stains deeply. When the chromosomes 
are being produced, the larger nucleolus of the egg cell gradu¬ 
ally ceases to stain, and it finally disappears. In the male 
pronucleus small nucleoli are present. 
Frenzel (’92) noticed in Carcinus moenas and in a species of 
Amphipod , in the ferment cells and “ Fettzellen ” of the hepa- 
topancreas, amitotic division of the nucleus, but no division of 
the nucleolus ; “sondern dass vielmehr an geeigneter Stelle 
des Tochterkernes noch vor der Abschniirung desselben ein 
ganz neuer Nucleolus entstehe, der alle Charaktere des ersten 
besitzt ” ; in this nuclear division one of the daughter-nuclei 
retains the whole original nucleolus. In similar cells of Idotea 
tricuspidata he found the nuclear division to be as in the pre¬ 
ceding species (but his Figures 8b, 10 , and especially 11 , would 
seem to represent stages of division of the nucleolus). 
