SCIENTIFIC PROCEEDINGS 



Abstracts of Communications. 

 Seventy-ninth meeting. 



Rockefeller Institute for Medical Research. 

 President Jacgues Loeb in the chair. 

 31 (1209) 



The intranuclear origin of the mammalian red blood corpuscles 

 observed in living cultures. 



By R. W. Tower and C. F. Herm (by invitation). 



[From the Department of Physiology, American Museum of Natural 



History, N. Y.] 



The present experiments on the origin of the mammalian (cat) 

 red blood cells were the outgrowth of a study to determine the 

 different stages in the development of the normoblast into a true 

 red corpuscle by means of a living culture of red bone marrow. 

 It was early found that the modern explanation of the formation 

 of the mammalian red blood corpuscle did not agree with the 

 activities observed in the cultures and that instead of witnessing 

 a normoblast re-modeled into a non-nucleated corpuscle by losing 

 its nucleus we saw this same normoblast sending out unnucleated 

 straw-colored bladders from its nucleus, these bladders finally 

 separating off as true red corpuscles. This process was not con- 

 fined to the normoblast type but was evident in the lymphocyte 

 series of white cells. Moreover our observations show that the 

 normoblast in the mammal (cat) and the red corpuscle in the bird 

 (chick) arise from white cells by an intranuclear activity and at 

 the time when they first emerge from the parent cell they are 

 almost indistinguishable from each other. 

 The principal results are: 



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