GERM CELLS OF COELENTERATES 395 
of the two substances. In some egg cells all the nucleolar frag- 
ments appear as non-chromatic, in others all appear to be mix- 
tures, and in still other eggs some of the fragments seem to be 
chromatic and some non-chromatic or mixtures; in no case were 
the fragments in one egg all chromatic. In some instances these -° 
differences have been indicated in the drawings by differences in 
shading. The term nucleolus is simply a general term, as used 
here, for it has some of the characteristics of a plasmosome and 
_ behaves in part as a karyosome. 
In the stage represented by figure 7 (about one-quarter the 
size of the mature egg) the fragmentation of the nucleolus begins 
and thereafter is characteristic, the variety in size and shape of 
these bodies being well shown in figures 6 to 16. The shape of 
the nucleolus is apparently of no significance, but the small 
spheres or spirals or the irregular masses as shown in figure 11 
and 12 would present a greater surface than a spherical body. 
This may be a matter of some importance. 
Of much greater interest is the condition shown in figures 7 to 
9, in which there is seen a sort of ring of finely granular matter in 
the nucleus near and inside the nuclear membrane. Let it be 
noted that the groundwork of the nucleus is reticular and the 
ring of granular matter is not reticular nor arranged with any 
reference whatever to the reticulum and it will then beevident 
that the nuclear reticulum and the ring of granular matter are 
not the same thing and are probably not directly related. Rather 
it is just the condition that we might find if there were a wave of 
matter spreading outward from the nucleolus toward the edge of 
the nucleus; this material, being somewhat different chemically 
from the nuclear sap and reticulum, it would present a different 
staining reaction. Figure 9, indeed, is proof that some such 
thing is happening, for, in addition to this ring of granular material 
in the nucleus, there is in the cytoplasm a radial arrangement of 
the small granules as though a similar current were passing out- 
ward from the nucleus into the cytoplasm. This same radial 
arrangement of cytoplasmic granules just outside the nucleus of 
the growing egg is very characteristic and continues up to a very 
late stage, indeed it is present just as long as there is nucleolar 
