500 WARO NAKAHARA 



Conklin ('03) observed amitosis in follicle cells in the termi- 

 nal segments of ovarian tubes of the cricket, at the time when 

 the cells are actively secreting the chorion, and the cells which 

 have once divided by amitosis never again divide mitotically, 

 but they degenerate after the formation of the chorion. He 

 said that amitosis is in this case, ''one of the last functions of 

 these cells and it is therefore an accompaniment of cellular 

 senescence and decsty." (p. 674.) 



Hargitt ('03) noted frequent occurrence of amitosis during 

 regeneration in hydroids, and recognized the inadequacy of 

 Flemming's theory regarding amitosis. 



Klemensiewicz ('03) considered blood-cells produced by mi- 

 tosis and by amitosis to be of equal biological value, and claims 

 that such cells originate normally by either method. 



Wasielewski ('03, '04) in his experimental work on the cells 

 of the root-tip of Vicia, demonstrated the fact that amitosis can 

 be induced by applying chloral hydrate to the cells, and such 

 cells, produced by amitosis, divide subsequently by mitosis and 

 show no sign of degeneration. He came to the conclusion that 

 amitosis and mitosis are not fundamentally different processes, but 

 they are to be regarded as two branches originated from a single 

 stalk. He also pointed out that there are two types of amitosis, 

 one initiated by the elongation of the nucleus which later takes 

 a dumb-bell shape and finally separates into two parts, the other 

 effected by the inward growth of a fold, which first occurs on 

 nuclear membrane. These are designated as destructive and 

 dissective types respectively. 



Child ('04) observed the frequent occurrence of amitosis in 

 the development of Moniezia and expressed his opinion that 

 amitosis may mean something more than degeneration and 

 aberration. 



Osborn ('04) interpreted amitosis in the food-ova of Fascio- 

 laria to be a futile attempt at segmentation, the cells having the 

 impulse to divide, but being powerless to do so by mitosis, fall 

 back on the easier mode of amitosis. 



Karpoff ('04, according to Nowikoff, '08, '10), working on 

 leucocytes, epidermis of amphibians, epithelium of the urinary 



