584 



Gideon S. Dodds. 



cells be distinguished. This explains the apparent increase in 

 number during this period. 



The nature of the evidence leading to this conclusion may be 

 briefly stated as follows: In some of the germ-cells and in no 

 other cells, of embryos of stages 6, 7 and 8 there was seen in the 

 cytoplasm a small round deeply staining body, about the same 

 size as one of the plasmosomes within the nucleus, or a little 

 smaller (figs. 21-23, 25-28). This I believe, is a mass of plas- 

 mosome material which has been separated and cast out of the 

 nucleus. 



Only a few cells showing this feature have been figured but the 

 number might have been multiplied because in every embryo of 

 these stages a considerable proportion of the germ-cells had this 

 body in the cytoplasm. On account of the manner of preserva- 

 tion of my material it was not possible to apply any stain which 

 would show positively whether this body was of the same nature 

 as a plasmosome within the nucleus, though the two stained sim- 

 ilarly with the stains employed. 



The following table gives for embryos of different ages the 

 number of germ-cells in one column, and opposite each, the num- 

 ber in which the extruded plasmosome was observed. 



TABLE 2. 

 Showing distribution of observed cases of extruded plasmosome 



In none of the above cases was the actual process of extrusion 

 observed, which indicates that the process must occupy but a 

 short period of time. There were cases observed, however, which 

 leave little doubt as to the nature of the extranuclear body and 

 the manner of its extrusion. This body was observed in no cell 

 in which both plasmosomes were of large size, but was quite 



