94 C. M. CHILD. 



ever, that elongation and division of the nucleolus is not a typical 

 feature of amitosis here. The nucleolus is always spherical or 

 nearly so. 



When amitosis occurs each part of the dividing nucleus usually 

 very probably always -- contains a nucleolus. Occasionally 

 it cannot be found but its apparent absence may be due to too 

 great extraction or to loss from the section. It is probable that 

 in Moniczia the formation of two nucleoli in a nucleus will be 

 followed sooner or later by division, though division need not 

 necessarily occur at once. 



The process of amitosis is simple as far as visible features are 

 concerned, but various apparent modifications occur. In some 

 cases a constriction in the nuclear membrane appears, extending 

 about the whole circumference of the nucleus or limited to one 

 side (Figs. 3, b, c, d, e; 5, a, b ; 7, e; 13, A, ., etc.). Fre- 

 quently there is a faint extension from the deepest part of the 

 constriction partly or wholly across the nucleus (Figs. 3, b, c ; 

 5, />, c ; 7, e, etc.). In other cases the formation of a nuclear 

 plate or membrane across some part of the nucleus takes place 

 before anything more than a very slight constriction appears in 

 the old nuclear membrane (Figs. 7, /, g ; 8, A, e ; 13, C ; 

 13, D, etc.). In such cases it is possible by careful focusing to 

 follow the new membrane across the whole diameter of the 

 nucleus. 



The method of separation of the products of division also varies 

 in accordance with the differences in the earlier stages. The 

 nuclei sometimes separate from one side (Figs. 3, c ; 5, c; 



7, e ; 15, B, b, etc.), such cases being presumably the result of 

 formation of the constriction from one side. Frequently also the 

 constriction appears to deepen uniformly about the whole cir- 

 cumference (Fig. 3, c/, e, etc.), separation being completed at or 

 near the middle. In those cases where a distinct nuclear plate 

 or partition forms across the whole nucleus separation seems to 

 occur simultaneously or nearly so over the whole surface (Figs. 



8, A, c, i ; 9, A, b, etc.). These cases are perhaps the most 

 demonstrative of all, for the flattened surfaces of the two nuclei 

 and occasionally their contact at one margin (Figs. 8, A, c ; 



9, A, b) leave no room for doubt that division has actually 



