398 
H. E. Jordan 
peciüiar shape of tlie products of nucleolar dissolution: splieric in the 
former, four lobed in the latter; and the difference in the process of their 
formation. 
Compared with Asterias forbesii, prenously described^), the nucleoli 
of Cribrella and Echinaster show an interesting contrast. In Asterias 
the nucleoli are compound structures consisting of a plastin and a clu’o- 
matin component; in Cribrella and Echinaster they appear wholly chro- 
matic. The lightly staining central portion of the persisting chief nu- 
cleolus of Cribrella in later stages is more probably transformed chroniatin. 
The reverse of this process is seen in the pronuclei of Asterias which are 
originally plasmatic but may become chromatic. EAÜdence from staining 
reaction indicates in these several cases a dose 
Physiologie relationship between the plasmatic 
and chromatic constituents of the nucleus. 
K. Hertwig’s^) Position that , . between 
plastin- and chromatin-nucleoli no sharp bound- 
ary exists“, and that . . between both forms 
of nucleoli transitions appear, and one can 
arise from the other“ (p. 714), receives support 
from the nucleolar changes seen in Asterias and 
Cribrella. 
When the egg is about 1/3 gi'own a number 
of beaded threads appear in the nucleus. Un- 
der low magnificatioii they remind one of the 
mossy chromosomes of the amphibian egg; in- 
deed , so does the entke nucleus with its 
many nucleoli, usually more abundant peripherally (fig. 3). These 
threads are always dose, and frequently attached. to a nucleolus. Very 
many of the nucleoli are seen to emit a small spherule about the size of 
a bead in the thread (figs. 5, 6 , 7, 8 , and 9). The nucleoli grow progres- 
sively smaller and less in number, and in the latest ovarian stages have 
almost disappeared. The eggs taken from the „brood-chambers“ show 
verv few or none at all. 
The beaded threads here are undoubtedly the chromosomes, as they 
1) JoRD.\x, H. E. The Relation of the Nucleolus to the Chromosomes in the 
Primary Oöcyte of Asterias forbesii (Papers Tortugas Lab. Vol. 1.) Carnegie Instn. 
Wasliington, Pub. 102. 1908. 
2) Hertwig, E. Lljer Kernteilung, Richtungskörperbildung und Befruchtung 
von Actinosphaerium eichhorni. Abhandl. K. bayer. Akad. WTss., lü. II, Bd. 19, Abt. 
III, 1988. 
Fig. 5. 
Chief nucleolns emitting one large 
(secondary) and two small(tertiary) 
nucleoli. This structure stains 
hlack in iron-hematoxylin and 
green in Anerhach's stain. X 800. 
