222 



O. C. GLASER. 



entoderm exhibits granulated nuclei imbedded in a granular 

 sometimes slightly alveolar ground substance in which cell 

 boundaries are indistinguishable. All the nuclei are surrounded 

 by a zone in which the particles are exceedingly dense, but this 



Fig. 2. A longitudinal section cut in plane xy of stage I., Fig. 9. On the right 

 (ventral, V. ) is shown the external kidney (ex.k.). Anteriorly A, where the 

 ectoderm {ect.) and the entoderm (ent.) meet is the cap of spongy tissue described on 

 p. 221. G.v. is the fragment of a germinal vesicle from one of the food ova. Note 

 the difference between the entoderm in this stage and that characteristic of the earlier 

 and later larvae. 



region does not always abut upon the nuclear membranes. In 

 many cases therefore a narrow clear band devoid of granules can 

 be seen between the nucleus and the dense zone. Often a 

 nucleus is found to contain a nucleolus, at times surrounded by 



