90 GEORGE T. HARGITT 



warrant their identification. On the basis of our present cyto- 

 logical knowledge I do not beUeve one would be justified in hold- 

 ing a view that there are chromatin granules of paternal and of 

 maternal origin which are homologous in form and function. It 

 would be desirable to have further evidence on the exact signifi- 

 cance and the precise method of synapsis, and an explanation 

 of its apparent absence, but no evidence can be offered from the 

 coelenterates I have studied. It may be added that in Tubu- 

 laria crocea there was clearly a stage of synizesis (G. T, Hargitt, 

 '09, figs. 30 to 33). 



The growth of the egg of Clava is much like that of Campanu- 

 laria, the food coming from the adjacent enteric cavity; there is 

 no absorption of degenerating oocytes as in Pennaria, Tubularia 

 and others. Growth begins, as shown by figure 4, before the 

 chromatin loops have formed a reticulum, and this may continue 

 for a time, as figure 5 illustrates. At about this period were 

 found particles of chromatin in the cytoplasm (figs. 5 and 6) in 

 the form of granules close to the nuclear membrane. Coincident 

 with further growth, more abundant chromatin granules appear 

 in the cytoplasm (figs. 7 to 9), and with the appearance of these 

 granules yolk formation takes place. There appears to be some 

 close relation between the passing of chromatin from the nucleus 

 into the cytoplam and the marked growth of the egg, and espe- 

 cially with the formation of yolk. . I am inclined to interpret 

 this as a causal relation, and think of the chromatin functioning 

 as an enzyme to elaborate (or break down, as the need may 

 demand) food in the cytoplasm. The early growth before emis- 

 sion occurs is due to the digested food of the enteric cavity fur- 

 nishing the substance and energy. This would mean that the 

 food in the enteric cavity is in a condition to be absorbed directly 

 by the egg and suffices for carrying on the ordinary functions; 

 but for the elaborating of reserve stuffs further changes are 

 essential and these changes are determined and conditioned by 

 the substances released from the nucleus. 



C. W. Hargitt ('06) calls attention to the appearance in the 

 living eggs of Clava ' ' at a certain stage of development of a deli- 

 cate, bluish, pigment, which gradually accumulated in amount 



