36 GEORGE T. HARGITT 



These fifteen coelenterate eggs support the claim of Jorgensen, 

 or at any rate are consistent with his suggestion of the relation 

 between the mode of nourishment of the egg and the size of the 

 nucleus. Perhaps this agreement is incidental, for there are some 

 objections to Jorgensen's views. His suggestion implies a pas- 

 sivity of the nucleus in eggs whose nourishment comes from 

 absorbed ova. I believe, in these as in the others, there is an 

 exchange of material between nucleus and cytoplasm of growing 

 eggs, for there is evidence of the passage of chromatin into the 

 cytoplasm of these eggs during growth. Nor does it seem prob- 

 able that the nuclei of accessory cells could have anything to do 

 in directing the growth processes, for in coelenterates these cells 

 are absorbed and their nuclei may undergo a degeneration before 

 absorption. All the facts sustain the belief that the nuclei of 

 growing eggs are responsible for the direction of the functional 

 activities of these cells. To this extent, at any rate, Jorgensen 

 is probably incorrect in his interpretation. I think it quite 

 probable that some relation may exist between the method of 

 nourishment and the relative size of the nucleus, and the figures 

 of the table may be an expression of this relation. 



3. Cytoplasmic inclusions 



In the cytoplasm of growing coelenterate eggs certain bodies 

 occur as characteristic structures. These inclusions, described 

 by the author ('13 to '18) as of nuclear origin, appear to be 

 correlated with the growth processes, either furnishing the stimu- 

 lus to growth or in some way determining the course and extent 

 of growth. Similar bodies are present in germ cells of other 

 animals at corresponding periods, but there is disagreement 

 regarding their origin and function. Without doubt, some of 

 the difference of opinion is due to the presence of cytoplasmic 

 inclusions of different sorts, both as to origin and as to function. 

 This is clearly established by the work of Cowdry ('16) and 

 other recent writers. 



In Campanularia the cytoplasmic bodies in the egg are formed 

 from the dissolving nucleolus and passed through the nuclear 

 wall into the cytoplasm, where they participate in the formation 



