THE EMBRYOLOGY OF THE HONEY BEE 235 



B 



M 



D 



o"Q 



W 



Fig. 94. Degenerating yolk nuclei. A, yolk cell, showing one large 

 vesicular nucleus, and three nuclei in each of which the chromatin has 

 become aggregated into a spherule. B, spherule leaving cell. C, spherule 

 lying just outside of cell. D, two spherules lying inside body of cell. E, 

 F, nuclei lying in the meshes of the protoplasmic reticulum, x 840. 



tion, the spherular masses of chromatic material, may have 

 emanated from the normal nucleus (Fig. 94, A and B). Fried- 

 erichs (1906) in the course of his investigations on the embry- 

 ology of the chrysomelid beetles, found that during the earlier 

 stages of development the nuclei of the germ cells of the ectoderm 

 and of the mesoderm, gave rise, by a peculiar kind of direct divi- 

 sion to structures resembling degenerating nuclei, which he termed 

 "paracytoids." These were not however thus formed in the yolk 

 cells, but since the nuclei of the yolk cells form precisely similar 

 bodies by ordinary nuclear degeneration, these too were termed 

 "paracytoids." In spite of this last mentioned circumstance and 

 in view of the frequent apposition of the dark-stained spherules 

 and normal nuclei in the yolk cells of the honey bee, it seemed 

 advisable to determine definitely whether any of these spherules 

 were derived by the emission of chromatic material from adjoin- 

 ing nuclei. A careful examination under high powers of all the 

 available sections of the stages during the formation of the 

 blastoderm shows conclusively that there is no evidence of a 



