196 ^^^ Philippine Journal of Science i»i6 



Sections from both adrenals showed a well-defined capsule of 

 white fibrous connective tissua Between this capsule and the 

 glandular substance is a narrow strip of vascularized young 

 connective tissue, in which irregularly shaped masses of cortical 

 and medullary cells were to be seen. The cortex of the gland 

 appeared as a narrow band of cellular elements surrounding 

 the medulla. This cortex is composed of a vascular reticulum 

 in the meshes of which cortical cells, polygonal in shape, are 

 arranged in vertical cords distinctly revealing the beginning of 

 of the zonas glomerulosa and fasciculata. Toward the periphery 

 these were granular and showed the characteristic fat granules 

 observed in adult cells; their nuclei, ovoid and round, filled from 

 one fourth to one half of the cell body and for the most part 

 were centrally located. Toward the center these cells gradually 

 merged with those of the medulla. The medulla, comparatively 

 more abundant than in adult adrenals, was separated at places 

 from the cortex by a large blood vessel. There is a distinct 

 vascular reticulum, the mesh spaces of which were filled with 

 irregularly shaped medullary cells, with large ovoid nuclei placed 

 centrally and almost filling the entire body of the cells. These 

 cellular elements were arranged in irregular branching masses 

 not unlike those of the parathyroid glands. The blood vessels 

 were for the most part thin-walled with a distinct endothelial 

 lining. 



Sections from masses "A," "B," "G," and "H" were apparently 

 identical. There was a thin fibrous connective tissue capsule 

 with adipose deposits at places, within which was a delicate, 

 vascularized connective tissue reticulum. The mesh spaces of 

 this reticulum were lined and contained large flattened and 

 irregularly ovoid cells with round nuclei centrally placed and 

 filling about one fourth or one half of the body of the cells. 

 Masses and isolated cells of lymphoid nature were to be seen. 

 These cellular elements were seen to be separated from the lining 

 of the sinuses and from the reticulum by narrow spaces. In 

 some sections, especially in those of *'H," small eosinophilic 

 cells were also observed. These cellular bodies were small lymph 

 glands. 



Sections from "D" were apparently made up of vascularized 

 embryonic connective tissue. 



EMBRYOLOGY 



In considering the embryology of the urinary excretory system, 

 especially in amniotes, we are at once impressed with the fact 

 that we are dealing not with a gradual development of one 



