THE ANATOMY OF THE PITUITARY BODY 



albinos — originates in the leptomeninges and, after develop- 

 ment, is found in the connective-tissue septa. 



The cells of the pars intermedia secrete the chromatosome- 

 dispersing hormone. If, however, the pars intermedia is rudi- 

 mentary and perhaps non-functional (man) or absent (fowl.^ 

 cetacean), the hormone is still formed by cells of the pars 

 glandularis. 



The basophilic cells of the pars neuralis have been care- 

 fully studied by numerous authors because of their possible 

 relationship to clinical disorders such as hypertension — a 

 view particularly emphasized by Gushing. These cells are 

 probably derived from the pars intermedia (Andreis, 1935; 

 and Rasmussen, 1936) and, it is generally agreed, increase in 

 numbers particularly after middle age, when, of course, essen- 

 tial hypertension is more frequently present. However, it ap- 

 pears clear that there is no convincing correlation between the 

 development or presence of hypertension and the ingrowth 

 (and hyperplasia) of basophilic cells in the pars neuralis. The 

 association of hypertension and this morphological change 

 is fortuitous (Marcano, 1935; Hawking, 1936; Rasmussen, 

 1936; and Scriba, 1936). Likewise these basophilic cells prob- 

 ably have nothing to do with the elaboration of the oxytocic 

 and pressor-diuresis-inhibiting hormones of the pars neura- 

 lis. The cetacean pars neuralis is entirely separated from the 

 pars buccalis by meninges and yet contains the character- 

 istic pars neuralis hormones (Geiling, 1935). In the cat, after 

 sufficient injury of the supraoptico-hypophysial nervous con- 

 nections, the amount of oxytocic and pressor hormones in the 

 pars neuralis is markedly reduced in association with atrophy 

 of the pars neuralis; yet there is little change in the pars 

 intermedia (Fisher and Ingram). 



The hyaline bodies of Herring, which can be found in the 

 pars neuralis of the whale (Wislocki and Geiling, 1936), are 

 therefore not derived from juxtaposed cells of the pars 

 buccalis (pars intermedia) as has been suggested from studies 

 of the pituitary of other mammals. In fact, Gersh and Tarr 



[II] 



