The relation of nucleoli to chromosomes in the egg of Cribrella sanguineolenta etc. 395 
F\s. 1 
Primary oöcyte of Cri- 
brella at the beginning 
of the growth period. Dia- 
meter of nncleus, 12 rai- 
crons. After staining with 
the hematoxylin-eosin 
combination the granulär 
cytoplasra appears purple, 
the nucleus pink and the 
nncleolns black. X 100. 
This description can embrace only the prematuration stages of the gro- 
wing oöcyte since even the eggs taken from the chamber (except one in 
the two-cell stage) had not yet formed their polo- 
cytes. From the standpoint of nuclear phenomena 
no significant changes had occured since leaving 
the ovary. This observation would seem to indicate 
that fertilization and maturation take place in the 
„brood-chamber“. 
The ovarian material was preserved in the corro- 
sive-acetic mixture. The stains employed were Hei- 
denhain’s iron-hematoxylin with eosin as a coim- 
terstain, Auerbach’s methyl green- acid fuchsin 
combination and thionin. The three stains gave 
absolutely consistent results. 
The youngest oöcytes (fig. 1) studied contain a 
comparatively large clear nucleus (dia. 12 microns) 
with an intensely chromatic (green in Auerbach’s stain) nncleolns. 
The cytoplasm is of the granulo-reticular type and stains a dark blue 
in the iron-hematoxylin eosin combination. In 
successively later stages the nucleolus enlarges 
considerably (figs. 2 and 4). The nucleus also 
grows in size and, while remaining finely gra- 
nulär (almost homogeneous), changes from an 
achromatic to a slightly chromatic (blue in iron- 
hematoxylin) condition. In Auerbach’s pre- 
parations it simply becomes more deeply red. 
The increasing amount of cytoplasm changes 
to a large alveolar type, acidophile in staining 
reaction. 
The point of primary interest however 
concerns the relationship between nucleoli and 
chromosomes. In the very earliest growth 
stages numerous secondary chromatic nucleoli 
begin to appear. They increase in number 
and may aggregate a hundred or more (fig. 3.) 
They vary considerably in size but stain inten- 
sely (green in Auerbach’s stain) until the 
final ovarian stage. They take origin from the 
primary nucleolus as smaller or larger chromatic spherules (fluid drops) 
which possibly continue to grow somewhat as they scatter through the 
Fiff. 2. 
Later stage of the growing oöcyte. 
The space ahout the nucleus is a 
tixation artifact. The granulo- 
reticular cytoplasm stains dark 
blue, the finely granulär or homo- 
geneous nucleolus red and the nu- 
cleolus black. A light pink zone 
envelops the nucleolus. X ■lüO. 
