1 8 RALPH E. WAGER. 



to that described by Doflein ('97) and Allen ('00) for the pseudo- 

 cells of Tubularia. I have found no cases of division of these 

 bodies. 



3. Pseudo-cells Derived from Nucleoll 



It has already been shown that the nucleolus of the nourishing 

 cell sometimes migrates out of the nucleus, leaving a broken and 

 partially destroyed nuclear membrane. After such a cell becomes 

 a part of the &gg the nucleolus may persist and form one of the 

 minute bodies so plentiful in the egg. Fig. 6, PI. I., shows the 

 nucleolus migrating out of a nucleus before the union of the cell 

 with the egg. 



Nucleoli and other bodies within the nucleus are also set free 

 in the egg cytoplasm by another process. Along the periphery 

 of the egg one often finds examples of the apparent fusion of the 

 cytoplasm of a cell with that of the egg followed by the enlarge- 

 ment of the nucleus in a manner slightly different from that 

 described in the processes concerned with the transformation of 

 whole cells into pseudo- cells. This condition was most common 

 in those preparations which showed the food spherules in the 

 nourishing cells. The outline of the nuclear membrane becomes 

 irregular, often presenting the appearance of the nucleoli as 

 being under an influence forcing them outward through the 

 membrane. The outhne of the nucleus may become twice as 

 large as that of the normal. Fig. 20, a and b, PI. III., are draw- 

 ings of such nuclei but are by no means as irregular as many 

 which wei-e found. Whether these peculiar conditions ever 

 result in the formation of a characteristic pseudo-cell or not, I 

 have been unable to determine. That they do not seems highly 

 probable. Their fate seems to be in the setting free of the 

 nucleoli by the breaking or absorption of the nuclear membrane. 

 Conditions which justify this conclusion are shown in Fig. 15, 

 PI. III., in which a nest of nucleoli are shown. Their appear- 

 ance and arrangement indicate that the nuclear membrane had 

 just disappeared as no trace of it could be seen. The minute 

 bodies differed slightly in their staining reactions as indicated in 

 the drawing. Probably, too, the metaplasmic bodies previously 

 described as occurring in the cytoplasm of the egg persist and 



