104 JOSE F. NONIDEZ 



The small lymphocytes may also differentiate into cells con- 

 taining acidophile granules. The latter first appear as very 

 minute bodies scattered in the thin layer of cytoplasm enveloping 

 the nucleus (fig. 29) . This second type of granule-laden cells may 

 be readily recognized, at least during the early stages, on account 

 of the structure of their nuclei and smaller size. As in the case 

 of the hemocytoblasts, the fate of the small lymphocytes is 

 sealed when the granules appear in their cytoplasm. These 

 granular cells eventually change into a smaller type of granulo- 

 cytes after constriction of their nuclei, losing the sphere and cen- 

 trioles along with their capacity for mitotic division. The trans- 

 formation of the small lymphocytes into granular elements was 

 very conspicuous in the myeloid metaplasis found in the ovary 

 of the pullet already referred to in the preceding pages. 



Other lines of differentiation in the small lymphocytes have 

 been described by several observers, but they are not apparent 

 in the connective tissue of the gonads, although they may pos- 

 sibly occur in these organs. Therefore, there is no need of men- 

 tioning them here. 



CONCLUSIONS 



1. In the gonads of the fowl, both in the embryo and mature 

 bird, there is a widespread tendency toward the formation of 

 blood-cells which usually appear grouped in lymphogranulo- 

 poietic foci. The elements of the myeloid group are represented 

 by cells loaded with acidophile granules. The cells of the lym- 

 phatic group appear in the form of small lymphocytes which are 

 a normal constituent of the tissue filling the spaces separating 

 the seminal tubules and ovarian follicles. Similar granulolym- 

 phopoietic foci also occur in other organs and in the general 

 mesenchyme. 



2. The granule-laden cells could be traced to elements with 

 basophihc cytoplasm deprived of granules. Such cells are the 

 hemocytoblasts (Danchakoft') or large lymphocytes. They arise 

 as a differentiation in the mesenchyme cells. Their origin from 

 the endothelium of the blood-vessels could not be established in 

 the gonads. 



