568 



MAYNARD M. METCALP, 



cavity composed wholly of follicle cells), fig. 9 (pharynx rudiments 

 composed chiefly of follicle cells) etc.]. 



Fig, G. Portion of a section of a young embryo of Salpa hexagona showing one 

 blastomere and fifteen mi.2;rated follicle cells. Bl blastomere, N nucleus of blastomere, 

 a, b, c, d, e, f, g, h, j, k nuclei of follicle cells ingested by the blastomere. )k( 1300 

 diameters. 



I wish now to call particular attention to my own observations 

 upon the nature of the disputed bodies within the protoplasm of the 

 blastomeres of Salpa. 



After having examined several hundred blastomeres all showing the 

 intra-protoplasmic bodies under discussion, I have selected a single 

 blastomere to figure and describe, not because there are not many 

 others showing a similar condition, but because this seems sufficient 

 to establish the point. The blastomere figured is one of five appearing 

 in a section of an embryo of S. hexagona at that stage of development 

 when the follicular epithelium of one half of the surface of the em- 

 bryo is most rapidly proliferating, about the stage shown in Bkooks' 

 fig. 2, tab. 11. The arrow indicates the direction of movement of 

 the follicle cells as they wander into the center of the embryo, where, 

 as described by Brooks, many of them degenerate. The figure is 

 carefully drawn with a Leitz Vi 2 immersion objective. 



