234 THE EMBRYOLOGY OF THE HONEY BEE 



relatively enormous size, like that shown in figure 92A. In a crude 

 and general way, both the number and size of the nuclei vary 

 with the size of the syncitia to which they belong. The largest 

 syncitia accordingly are commonly found to contain a consider- 

 able number of relatively enormous nuclei ; as shown in figure 

 92A. All of the yolk syncitia possess branching processes which 

 are continuous with the threads of the delicate protoplasmic 

 network remaining within the yolk subsequent to cleavage, and 

 are thereby placed in direct connection with one another. In a 

 broad sense therefore the entire protoplasmic contents of the 

 yolk forms a single syncitium, directly comparable to that of the 

 cleavage cells. 



A large proportion of the nuclei of the yolk syncitia — in the 

 narrow sense — show plain evidences of degeneration. A survey 

 of the preparations covering this period shows that the changes 

 are as follows : The nucleus decreases in size and the entire 

 contents of the nucleus assumes a darker shade, while the chro- 

 matin at the same time becomes gradually agglomerated into two 

 or three irregular dense masses, which finally become united into 

 one as the nucleus continues to contract. The last observed stage 

 in this process is a densely stained and relatively minute sub- 

 spherical mass, as shown in figure 94, A-D. A similar agglomer- 

 ation of the chromatin in the degenerating nuclei of the yolk 

 cells has been observed by Wheeler (1889) in Leptinotarsa 

 (Doryplwra) and by Friederichs (1906) in Donatio.. Since the 

 nuclear membrane is intact at all stages of degeneration, it neces- 

 sarily follows that the karyolymph is lost by diffusion, passing 

 out into the surrounding cytoplasm which often takes on a lighter 

 hue about such nuclei. The masses of chromatin formed during 

 nuclear degeneration are located in various parts of the nucleus, 

 in some cases at the center, in some around the periphery, in 

 others at one side. It thus happens that in some instances a 

 densely stained spherule is seen lying on the internal wall of a 

 small vacuole (Fig. 94E), the latter representing the empty 

 space left within the nuclear membrane. In the majority of cases 

 the degenerating nucleus for some unknown reason lies at first 

 close to a normal nucleus, so that during the late stages of degen- 

 eration the appearance suggests that the products of degenera- 



