GERM CELLS OF COELENTERATES 411 
CONCLUSIONS 
The egg cells of Campanularia flexuosa arise in the entoderm 
of the pedicel of the gonophore, by the transformation of a single 
epithelial cell, or from the basal half of a divided cell, the distal 
half of which remains an epithelial cell and retains its epithelial 
functions. Therefore the egg cells have come from differentiated 
body-cells (so-called) and there is no differentiation of the germ- 
plasm in the sense that germ cells are early differentiated and set 
aside and do not participate in the body functions. Any cell of 
the entoderm of Campanularia flexuosa may become an egg cell 
if it is in the position of the developing gonophore. ‘There is no 
division of the primitive egg cell but each transforms directly into 
a single mature egg cell. 
' The chromatin of the primitive egg cell, at first arranged in 
definitely arranged loops, disappears, forms a fine-meshed delicate 
reticulum and a nucleolus (the latter also contains non-chromatic 
matter). 
The nucleolus becomes greatly vacuolated, breaks up into frag- 
ments of various sizes and shapes, and the chromatin contained 
in these passes through the membrane of the germinal vesicle to 
form the chromidia in the cytoplasm. Co-incident with this 
chromatin emission, the rapid growth period of the egg begins. 
So long as the dissolution of the nucleolus continues there is a 
considerable outflow of material from the nucleus, shown by cur- 
rents in the cytoplasm. The chromatin particles in the cytoplasm 
become, or have something to do with the formation of the yolk 
bodies. Yolk formation, chromatin emission, strong currents 
from the nucleus, and growth of the egg cease when the nucleolus 
has disappeared. The nucleolus is, then, a dynamic center, con- 
cerned primarily with the nutritive activities of the egg cell. 
It also aids in the formation of new chromatin. 
The nuclear reticulum is apparently unchanged by the dissolu- 
tion of the nucleolus, but when the nucleolus has disappeared, 
or nearly so, the chromatin of the reticulum forms the chromo- 
somes. ‘There is not the formation of a spireme and not always 
the formation of strands in the reticulum, but the chromosomes 
may form by the segregation of the chromatin granules of the 
