98 The Philippine Journal of Science I'ois 



As an introduction, some consideration of the histology and 

 physio-pathology of the pituitary body may be recorded. 



The anatomical formation peculiar to the gland is that of 

 a pea-shaped mass, connected to the base of the encephalon by 

 means of a delicate peduncle. It weighs generally from 3 to 6 

 decigrams, and occupies a cavity in the cranial floor called the 

 "sella turcica." It consists of an anterior and a posterior por- 

 tion, together Avith a ramus or infundibulum. The anterior or 

 glandular portion consists of a stroma of connective tissue, 

 rich in capillaries, in which are closely packed epithelial cells 

 grouped in the form of acini. The cells which constitute these 

 acini are polyhedral, round, or oval, and are of two principal 

 varieties, chromophilic and chromophobic. In the chromophilic 

 cells the cytoplasm is abundant and contains granules which are 

 stained red or yellow with eosin or take a purple coloration with 

 hsematoxylin. Klotz(l) has remarked the constant presence of 

 acidophilic, mononuclear cells. The chromophobic or principal 

 cells are smaller, more numerous, and have a transparent 

 protoplasm. According to Berkeley, (4) the nerve elements are 

 derived from the sympathetic plexus of the carotid. At the 

 periphery of the lobe and particularly at the boundary line 

 between the two lobes, the so-called pars intermedia, the acini, 

 surrounded by cubical cells, are often distended by a colloid 

 substance, which is also present in the lymphatic and vascular 

 spaces. 



The posterior or infundibular portion of the gland is com- 

 posed of vascular connective tissue, in which exist numerous 

 fusiform or stellate cells which are often pigmented. The 

 structure is practically that of the neuroglia. Berkeley (4) has 

 reported the presence of ganglion cells and of varicose nerve 

 fibrils, but K6lliker(l) denies the existence of nerve elements 

 in this portion of the gland. 



At the line of junction between the two lobes, the vessels are 

 particularly numerous, and in man there is a bilobular cavity 

 bounded by cylindrical epithelium. 



Physiology. — The nature of the function of the gland, although 

 obscure as yet, is becoming more and more clear. Evidence is 

 accumulating which tends to prove that, like the thyroid and the 

 suprarenals, it belongs to the group of ductless glands, and that 

 it elaborates an internal secretion essential to metabolism. As 

 regards its vascularity, presence of acini, and lymphatic vessels 

 containing colloid, a close analogy exists with the thyroid, which 



