PLATE 2 
Platygaster hiemalis 
All figures drawn 2,255 times natural size. 
A. —Egg one hour after deposition, with nucleus and sperm. 
B. —Egg about one and one-half hours after deposition. Nucleus condensing. 
C. —Egg 2 hours old. Chromosomes of nucleus are again evident. 
D. — Egg 4 hours old. Nucleus is at prophase and sperm is curled. 
E. —Egg about 4 hours old, showing first maturation spindle. The sperm or male 
nucleus is spindle-shaped. 
F. —Like figure E but at a slightly later stage. The anterior part of the spindle 
becomes the first polar body and the posterior part becomes the oocyte nucleus of the 
second order. 
G. —Egg showing first polar body which remains in the egg, oocyte nucleus, and male 
nucleus. 
H. —Like Figure G but at slightly later stage. 
I. —Egg about six hours after deposition. Polar body condenses to become an irreg¬ 
ularly shaped mass of chromatin while the oocyte nucleus of the second order expands 
slightly. 
J. —Like Figure I, but at slightly later stage. 
K. —Egg about 7 hours old, showing the first polar body, second maturation spindle, 
and male nucleus. 
L. —Seven-hour-old egg. 
M. —Second maturation about complete. The anterior part of the spindle becomes 
the second polar body while the posterior part becomes the female pronucleus. 
N. —Egg eight hours after deposition. The first and second polar bodies are found 
close to each other in the anterior end of the egg, which is known as the polar region. 
O. —Egg 10 hours old. The first and second polar bodies approach each other. 
Female pronucleus is in center of the egg and male nucleus is usually in the posterior 
or embryonic region of the egg. 
P. —Slightly later stage than Figure O. Polar bodies are fusing. 
Q. —Egg about 11 hours after deposition, with a single polar nucleus (two fused polar 
bodies) in anterior end. The male and female pronuclei expand. 
R. —Egg 12 hours old. Polar nucleus elaborates in anterior end of the egg. 
S. —Like Figure R, but male and female pronuclei are found close to each other 
in the posterior region of the egg. The male pronucleus is always smaller than the 
female jpronucleus. 
T. —The male and female pronuclei are about to fuse. 
U. —Fusion of pronuclei in posterior region of egg. The chromatin of the polar 
nucleus breaks up. 
V. Parthenogenetic egg 24 hours old showing polar nucleus, and segmentation 
nucleus which has maturated twice like fertilized egg. 
W. —Fertilized egg about 24 hours old, with polar nucleus showing particles of 
chromatin scattered over a reticulum and segmentation nucleus in a resting stage. 
The egg is usually surrounded by host tissue at this stage. 
X. —Egg from 1 to 2 days old. During this interval the embryonic region containing 
the segmentation nucleus becomes differentiated in the posterior part of the egg. 
