196 C. M. CHILD. 



Figs. 28 and 29, A-2g, D. Figs. 30, A-C (PI. XIII.), show 

 cases in which they are somewhat larger, and in which the 

 method of their formation is more clearly visible. In these cases 

 the new nuclei are nearly hemispherical in form and appear as if 

 growing or budding out from the cavity representing the old 

 nucleus into the cytoplasm about it. Whether the method of 

 formation is actually the same in all cases is doubtful ; some- 

 times the new nuclei seem to lie wholly within the cavity as in 

 Figs. 29, A and 29, B (PI. XII.). But there can be no doubt of 

 their formation. The newly formed nuclear membrane is quite 

 distinct and the whole process presents a very characteristic 

 appearance. 



The number of deeply staining bodies visible within these 

 small nuclei depends on the fixation and staining. If extraction 

 is carried beyond a certain point only one dark body retains the 

 stain : otherwise several may be visible, one or two of which are 

 usually larger than the others. After chrom-oxalic the stain is 

 more readily extracted from all except the one body and with 

 the usual degree of extraction only the one body appears. Figs. 

 29, ^29, D, are from such preparations. In nearly all cases 

 the nuclei stain somewhat more deeply throughout than the 

 cytoplasm as is indicated in the figures by stippling. 



Whether the number of new nuclei formed is always the same 

 is uncertain but it is probable that as many as three or four and 

 perhaps more new nuclei may arise from one old nucleus. In 

 Fig. 29, E (PI. XII.), four small nuclei lie near the lower nuclear 

 cavity but some of these may have arisen from another nucleus. 



Figs. 3136 (PI. XIII.), show what I regard as later stages in 

 this process. In the group shown in Fig. 3 1 two spermatocytes 

 were apparently involved and the two old nuclear cavities are 

 still visible, though very irregular in form and divided by strands 

 of cytoplasm. One of the old nucleoli is visible, the other lying 

 in another section. Judging from their position three of the 

 small nuclei were formed about the cavity on the right and one 

 on the other : in the next section more small nuclei were found 

 which probably belonged to the nuclear cavity on the left but in 

 this section other adjoining nuclear cavities with other small 

 nuclei appeared, so that certainty was impossible. It is of in- 



