THE EMBRYOLOGY OF THE HONEY BEE 165 



each (Fig. 55, DegCl). Degenerating cells become evident in 

 these regions as early as Stage IX, and are easily recognizable 

 at low magnifications by the presence among the brain cells of 

 deeply stained granules. Under a high magnification these gran- 

 ules prove to be the remains of the chromatic contents of the 

 nuclei of degenerating cells (Fig. 62). Such nuclei are spherical 



Am 



FIG. 62. Part of the section represented by fig. 56, showing degenerat- 

 ing cells in the protocerebrum, x 600. 



in form and smaller than the adjacent nuclei, the nuclear mem- 

 brane often faint. The chromatin generally appears to be con- 

 densed into one or more relatively large granules, and large and 

 deeply-stained spherical nucleoli are also commonly present. 

 Janet (1907) has observed very similar nuclei in the degenerating 

 wing muscles of an ant (Lasius). The cytoplasm of the degen- 

 erating cells becomes broken up into a number of minute spherules, 

 producing an appearance suggestive of an emulsion (Fig. 62). 

 This process of cell degeneration continues up to the time of 

 hatching, and probably even later, but the number of degenerating 

 cells present in the brain reaches its maximum at Stages XIII 

 and XIV (Figs. 56 and 62). At this time not only do the regions 

 referred to appear to be crammed with degenerating cells, but a 

 large number of the superficial cells of the protocerebral lobes, 

 as far back as the optic lobes, are also in a state of degeneration. 



