THE PITUITARY BODY 



distance over the surface of the brain. It is easy to under- 

 stand, also, that great care must be exercised in removing the 

 pituitary so as not to injure the ill-understood but important 

 nerve tracts and nuclei of the overlying tuber cinereum, 



A number of investigators have studied the relationship 

 between pituitary weight and body-weight or stature. Such 

 studies, however, do not take into account the complexity of 

 the gland's structure and function. The correlations found 

 depend in a large measure on the heaviest part of the pitui- 

 tary body, the pars glandularis. Data from more useful 

 studies are summarized in Tables I and II. After puberty the 

 female pituitary is usually the heavier (the woodchuck is an 

 exception). Usually, also, the pituitary of pregnancy is heavi- 

 er than that of the non-pregnant female. This is particularly 

 true of man. Freeman (1934), as well as others, have studied 

 the relationship of the weight of the whole pituitary of men 

 to weight, stature, and race. He reported that the pituitary 

 weight is better correlated with body-weight than with stat- 

 ure, and that the pituitary of the negro is heavier than that 

 of the Caucasian if the pituitary weights of the same sexes are 

 compared. Freeman summarized the literature on the corre- 

 lation of the pituitary weight with other variables and con- 

 cluded, inter alia^ that there may be some decrease in pitui- 

 tary weight with age but that the change is slight. One of the 

 most elaborate studies in animals is that of Hammar (1932) 

 in the rabbit. 



The specific gravity of the adult human pituitary is about 

 1.054 (Scheele, 1929). 



The relationship between the meninges and the pituitary 

 has been studied by Hughson (1922, 1924) in the dog and cat 

 and by KoUer (1922) in a number of mammals. According to 

 the latter, a complete dural diaphragma sellae is to be found 

 only in man. The diaphragm is incomplete in the ox, small 

 ruminants, pig, dog, and cat. In the horse there is no dia- 



[6] 



