DEVELOPMENT AND FUNCTION OF HEMAL NODES 401 



species, was independent of the number of sucli nodes present. 

 Warthin '01 who held that the formation of erythrocytes un- 

 doubtedly occurred in disease also suggested a cyclical activity 

 and added that "the appearance (in disease in man) often sug- 

 gests a transformation of adipose tissue into lymphoid tissue 

 and the possibility of a physiological rotation of the two forms 

 of tissue." 



Gutig '07 found germinal centers composed of normoblasts 

 and nwelocytes rarely present in hemolymph nodes of the pig 

 and hence concluded that the assertion that hemolymph nodes 

 serve only as seats of blood destruction can not be accepted. 



V. Schumacher '12 on the other han,d, thought it possible that 

 individual erythrocytes are formed in the hemolymph nodes of 

 the sheep but regarded such an origin of erythrocytes as a very 

 subsidiary one. v. Schumacher also reported phagocytosis by 

 reticulum cells and a fragmentation of erythrocytes within 

 phagocytes in some hemolymph nodes but the occurrence of 

 extracellular fragmentation or degeneration of erythrocytes as 

 observed bj^ Weidenreich is denied, v. Schumacher like myself 

 also observed but few pigment cells. 



That the destruction of erythrocytes both by extra- and intra- 

 cellular disintegration and hemolysis and the formation of leuco- 

 cytes occur within hemal nodes is undoubted. That these 

 processes vary extraordinarily in degree within different nodes 

 of the same individual species, as well as in those of different 

 species is also evident. I fully realize that it is rather venture- 

 some and often quite futile to draw conclusions regarding func- 

 tion from a purely morphological basis, yet it seems to me that 

 the supposed function of 'blood destruction' has been wholly 

 over-emphasized. Moreover, it might pertinently be suggested 

 that it is after all not 'blood destruction' but mainly destruction 

 of erythrocytes which is apparently so preeminently a charac- 

 teristic of some hemal nodes. Nevertheless, since so many 

 h,emal nodes contain so very little blood even when practically 

 depleted of ]\anphatic tissue, it is highly improbable that de- 

 struction of erythrocytes is the chief or even as important a func- 

 tion of hemal nodes as would seem to be the case upon cursory 



