134 BOTANICAL GAZETTE [febrtjaiy 



not too small they bud off other small nuclei in the same manm 

 (fig. 18). This process usually continues till all the nuclei in the cy 

 arc approximately equal in size (figs, i, 2). Sometimes all the 

 daughter nuclei given off are so much smaller than the parent that 

 the mother karyosome is never divided up among the daughters, but 

 remains behind full size, after giving up its chromatin, like the 

 nucleolus in the prophases of mitosis. In this case the large nuch 

 degenerate and leave the small ones as the functional nuclei of the 

 cyst. Fig. 20 shows the first indication of this in the vacuolate karyo- 

 some of the parent nucleus. In fig. 21 all the chromatin has migrated 

 from the old karyosome but some of the small karyosomes still 

 remain inside the nuclear membrane. The larger of these are about 

 the same size as the numerous small nuclei of the cyst. Fig. 22 

 shows another large nucleus from the same cyst, which is entirely 

 bereft of chromatin. Fig. 23 is the last stage of the process; here 

 the old nuclear membrane has disappeared and the faintly staining 

 old karyosome (nucleolus) lies naked in the cytoplasm. Beside it 



is shown one of the functional nuclei. 



conclusion that the nuclei derived by these processes of amitosis are 

 normal, and that they with their descendants become the functional 

 nuclei of later stages, capable of perpetuating the species. 



We 



GENERAL 



Although the processes by which these nuclei are derived an 

 nova, the formation of normal tissue by amitosis is by no mean 



Zul "' C ' M ' CHILD ( j -5) has recently shown that 



embryf 



amitosis 



and ,n some adult animals. He records instances from most of the 



CTcat animal rO^ri,. • i » . i _ 



worms, trematod 



estooes, msects, amphioxus, fishes, amphibia, and birds. In the, 



e,Zr- 1 T ary t0 What Would be expected, there seems to be no 

 especial distinction k„+,. — .i . ' . .. 4* 



nrimr* „f t l. , awiiid clIlU me germ UlilhUl ao ~ 



ongm of the nude,. I„ Moniezi , , sh „ hk h 



germ 



spermatogonia may even undergo a sort 



, • w "*-**« oy wnich sperms 

 through mltr^c'c. 



In general, amitosis is most common 



in 



