THE LYMPH-NODES. 401 



nodes in which blood has accumulated from hypersemia or haemorrhage, and the sinuses 

 containing blood may be injected from the blood-vessels. In the most typical forms of 

 hsemolymph nodes, the cortical and medullary portions are not well denned and the 

 germinal areas in the lymphoid tissue are less marked than in lymph nodes. Many 

 large cells, probably proliferated endothelium, containing red blood-cells and blood pig 

 ment, are usually present in the lymph sinuses. In addition to these, phagocytic cells, 

 eosinophiles, and mast cells may be present. 



In the opinion of Warthin, 1 who has made especially careful studies of these struct- 

 ures and of others, they are inconstant or variable organs related to but distinct from 

 lymph-nodes, and having special hsemolytic and possibly other functions. The studies 

 cf Dayton in general confirm the conclusions of Warthin. 2 



1 For a full and excellent summary of this subject, with bibliography, consult War- 

 fkin, Trans. Chicago Pathological Society, November 12th, 1902. For a study of the 

 development of hsemolymph nodes in adipose tissue, see Proc. Path. Soc. of Phila., 

 December, 1903. 



'* Dayton, Am. Jour. Med. Sciences, vol. cxxvii., p. 448. 



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