790 J. P. SIMONDS 



hypophysis without giving details as to their location or character. In 

 each of two hypophyses in my collection there was present in the posterior 

 half of the neurohypophysis an isolated "island" of large cells, with 

 abundant cytoplasm filled with sniall vacuoles and with deeply staining 

 oval nuclei located in the periphery of the cells. (Fig. 5.) In serial sec- 

 tions these masses were found not to be connected with the anterior lobe. 

 These cells do not resemble any of those commonly found in the anterior 

 lobe. 



There is normally present at about the center of each lateral half of 

 the anterior lobe a mass of connective tissue from which smaller bands 

 radiate to form the delicate stroma of the gland. In these masses of fibrous 

 tissue there are normally several blood vessels. In a considerable per- 

 centage of hypophyses these vessels are increased in number and size so 

 that the whole central mass is composed of wide blood spaces separated by 

 narrow bands of connective tissue, thus resembling a so-called hemangioma 

 cavernosum of the liver. (See Fig. 6.) Evans and Assinder have 

 described an angioma of the hypophysis. 



Aplasia, Hypoplasia and Atrophy 



Absence of the hypophysis has been discussed in the paragraphs on 

 Malformations. 



In dwarfs the hypophysis has been found hypoplastic by Hutchinson 

 and Sternberg(&). The under development affected the anterior lobe 

 chiefly. In Hutchinson's case this lobe formed barely one-third of the 

 total mass of the gland, instead of the normal five-sixths. 



Atrophy of the hypophysis may be either primary or secondary. Pri- 

 mary atrophy occurs quite constantly in old age and is an expression of 

 physiologic regression on the part of the gland. The upper surface sinks 

 in, thus deepening the pit which is normally present there and causing an 

 apparent lengthening of the infundibulum. There is almost constantly 

 an accompanying increase of connective tissue, and frequently a simul- 

 taneous widening of the blood vessels. This senile atrophy of the hy- 

 pophysis is often accompanied by, and probably partly due to chronic 

 endartcritis (Cagnetto (&)). The epithelial cells of an atrophic gland 

 diminish in size ; their cytoplasm becomes less granular, and the nuclei 

 are usually smaller and stain more deeply. In such an hypophysis there 

 may be localized areas in which the cells appear to be hyperactive, and are 

 crowded with granules and vacuoles. Primary atrophy does not appear to 

 induce symptoms of hypopituitarism. 



Diminution in size, a sort of temporary atrophy, of the anterior lobe 

 has been described by Gushing and Goetsch(fr) and by Mann in hibernating 

 animals. 



