440 WILLIAM H. F. ADDISON 



globin-bearing fragments of erythrocytes, as indicated by color 

 comparison with adjacent red blood corpuscles. Not infre- 

 quently, too, a splenocyte is seen containing a polymorphonuclear 

 leucocyte. 



These polymorphonuclear leucocytes in the rabbit are con- 

 spicuous, for in addition to the characteristic shape of nucleus, 

 their numerous fine cytoplasmic granules stain a vivid red color 

 with stains containing eosin. This coloring may lead to some 

 confusion at first in distinguishing them from true eosinophiles. 

 However, the fact that the granules in the latter are larger than 

 in the ordinary polymorphonuclears, and also that their color 

 after eosin staining is more yellowish, helps one to distinguish 

 between them. 



SPLEENS OF EXPERIMENTAL ANIMALS 



After injection of the pigeon blood, prepared in the manner 

 above described, the corpuscles retain their individuality for 

 but a short time. At the end of one hour they are found to be 

 swollen, rounded, and the nucleus has lost its characteristic 

 staining capacity. Most of the corpuscles are single, but some 

 have begun to agglutinate into little masses. In some elements, 

 the nucleus is still distinguishable by its refractivity. Brown- 

 Sequard, in 1857 (Hunter, '01, p. 120), noted that while dog or 

 rabbit corpuscles injected into the circulation of the domestic 

 fowl could be found at the end of a month, the corpuscles of the 

 fowl injected into the dog or rabbit were no longer recognizable 

 at the end of one hour. Our preparations, in the main, confirm 

 the latter observation. 



At this stage, the spleen has grossly a purplish-black color, 

 and its channels are congested with the masses of intermingled 

 rabbit and pigeon corpuscles. It was found that perfusion was 

 even less successful than usual in washing out the blood. A few 

 splenocytes containing inclusions recognizable as entire pigeon 

 corpuscles are seen, but splenocytes with inclusions of amorphous 

 brownish masses are more often to be found, but not in every 

 field, as viewed with the ^ oil-immersion lens. Polymorphonu- 

 clears are seen more frequently than in the normal spleen, and 



