No. 2.] COMPARATIVE CYTOLOGICAL STUDIES. 561 
EXPLANATION OF PLATES XXI-XXX. 
All the figures have been drawn with the aid of the camera lucida, and rep¬ 
resent sections of the structures delineated. Those parts of them which are 
colored represent as accurately as possible the stained preparations from which 
they were copied; in most of the figures only certain portions are colored, the 
other details being filled in with the pencil. In order to show the correct pro¬ 
portionate size of the various cells and nuclei the greater number of the figures 
have been made at a magnification afforded by the homogeneous immersion lens 
T a 2 of Zeiss, with the ocular 4, and unless otherwise specified this may be under¬ 
stood to have been the magnification employed. The following abbreviations have 
been used in the figures: 
c. 
cell. 
N.P. 
metamorphosed portion of 
C.D. 
cell duct. 
nucleus. 
Cen. 
centrosome. 
N. Sap. 
nuclear sap. 
Chr. 
chromatin. 
Nut. Gl. 
nutritive globule. 
Chr. F. 
chromatin filament. 
n. 
nucleolus. 
Chrotn. 
chromosome. 
n. 2. 
nucleolus of the second gen¬ 
C. Mb. 
cell membrane. 
eration. 
C.Sp. 
centrosphere. 
n. D. 
derivatives of the nucleolar 
C. T. N. 
nucleus of connective tissue. 
substance. 
C. T. S. 
connective tissue sheath of 
n. Gr. 
granules of degenerated nu¬ 
the ovarial acinus. 
cleoli. 
Cut. 
cuticula. 
n. Mb. 
nucleolar membrane. 
Cy. PI. 
cytoplasm. 
nn. 
nucleolinus. 
d. C. 
degenerated cells (or cell 
n. Sub. 
nucleolar ground substance. 
substance). 
n. Vac. 
nucleolar vacuole. 
End. PI. 
endoplasm. 
nx. 
nucleolar body of unknown 
Gon. Mb. 
gonadal membrane. 
origin. 
Iv. Mb. 
intravitelline membrane. 
Ps. n. 
pseudonucleolus. 
N. 
nucleus. 
Seer. 
secretion corpuscles. 
N. Bd. 
problematical nuclear body. 
Sp. 
spores. 
N. Fib. 
nuclear fibers. 
Sp.F. 
spindle fibers. 
N. Gr. 
nuclear granules. 
Vac. 
vacuole. 
AT. Mb. 
nuclear membrane. 
Yk. Bl. 
yolk ball. 
Yk. Gl. 
yolk globule. 
