8 RALPH E. WAGER. 



in it are a number of minute bodies apparently identical with 

 those described as occurring in the primitive ova, and set free 

 here by the coalescence of the cells. Some of them, however, 

 are doubtless nucleoH, or at least nucleolar bodies, which, by 

 the same process, have been added to the already rather complex 

 egg mass. 



The egg now continues to increase in size by the further 

 appropriation of the cells surrounding it. The cells thus con- 

 tributing their mass to that of the egg may undergo a regressive 

 change similar to that described for the large ova which unite to 

 form the growing egg. One of the primitive ova, or possibly at 

 this time rightly called nourishing cells, becomes conspicuously 

 larger than its fellows ; its nucleus becomes correspondingly 

 large and the regressive changes above described are repeated 

 here. The chromatin assembles in a loosely coiled coarse 

 spireme ; the nuclear membrane disappears ; the nucleolus be- 

 comes very large and frequently filled by a vacuole ; the cell 

 wall between this large cell and the egg gradually becomes ab- 

 sorbed and the two unite. Such a process in an intermediate 

 stage is shown in Fig. lo (PI. II.) in which the nuclear mem- 

 brane of the nourishing cell has entirely disappeared on one side 

 and the chromatin filaments are broken up into short pieces. 

 Two metaplasmic bodies are noticeable in the large cell as well 

 as in the egg itself Their probable origin has been discussed 

 above. Fig. 9 (PI. II.) represents a stage a little later than that 

 above referred to. Outside of the egg is a large non-nucleated 

 mass two or three times the size of the ordinary cells. Near it 

 and next to the egg is a smaller cell in which these regressive 

 changes are well advanced. The cell-walls between these two 

 bodies is less distinct than in the other cells in the field, suggest- 

 ing that the two would eventually unite, before union with the 

 egg. Such conditions as this are not at all rare, and suggest that 

 these large cells are developed by the union of two or more of 

 the nourishing cells rather than by the growth of any one to this 

 unusual size. Having reached this stage the large mass then 

 becomes a part of the egg by the disappearance of the wall 

 between the two bodies, thus setting free into the substance of 

 the egg the chromatin strands, nucleoli and nucleolar bodies as 



