186 JOHN STEPHENS LATTA 



The other type of eosinophile found here is quite variable in 

 shape according to its immediate surroundings, being sometimes 

 rounded and again quite elongate, spindle-shaped, or irregular 

 in contour. The nucleus is of an entirely different appearance 

 than that of the first type, never being of an extreme polymor- 

 phous shape. It does, however, present variations in shape, 

 sometimes appearing as one dense, round nuclear mass, and 

 again appearing as two round masses, lying either side by side 

 in the cell or widely separated at opposite sides of the cell. The 

 cell body of these cells is very closely packed with particles, 

 which are definitely rod-like and elongated. These rod-like 

 particles stain a,n intense dark red when compound blood stains 

 (Nochts Hastings, eosin-methylene blue) are used. 



The first type, the blood eosinophile, is very evidently the same 

 as Hartmann found in the neighborhood of the intestinal tonsils 

 (of the rabbit). It is the first type to appear in the connective 

 tissue at this place, the connective-tissue eosinophile not being 

 found until between the first and second weeks of postfetal 

 life. The blood type of eosinophile is never found in large 

 numbers, except under pathological conditions (such as presence 

 of parasites, etc.). It seems very evident that they, as Hartmann 

 thought, are carried into the connective tissue and dropped there 

 by the blood stream. No developmental forms are found to 

 indicate a possible local formation of this type of cell. 



On the other hand, there is evidence to indicate that the 

 connective-tissue eosinophiles, found so abundantly in close rela- 

 tionship with the intestinal tonsils, are formed in situ at the 

 expense of lymphoid hemoblasts also developing there (figs. 

 9, 10, 14, 16). 



This process of development was found to be exceedingly diffi- 

 cult to follow because of the scarcity of developmental stages. 

 This is accounted for by the great rapidity of the formation of 

 the eosinophile granules after they have begun to differentiate 

 out. Quite a few cells were found, however, the cytoplasm of 

 which was only slightly basophilic, or colorless, which contained 

 a few scattered, round eosinophihc granules (dark red). The 

 nuclei of these cells were identical with those of lymphoid hemo- 



