THE PITUITARY BODY 



logical and pharmacological support for this view is, however, 

 weak and will be discussed in the chapters dealing with the 

 hormones of the pars neuralis. 



The transport of internal secretions from the pituitary body. — 

 The routes by which the internal secretions of the pituitary 

 body may be conveyed to the rest of the organism have been 

 subjected to much anatomical study since Herring's pioneer 

 work (1908). It is generally agreed that most of the secre- 

 tion(s) of the pars glandularis are removed by way of the rich 

 network of vascular sinusoids, of which probably only a small 

 number empties into the hypophysio-portal vessels. Con- 

 ceivably some secretion could also escape into the cerebro- 

 spinal fluid by way of the arachnoidal sheaths of blood 

 vessels. 



The pathways of secretion of the pars intermedia and pars 

 neuralis are matters of controversy lacking satisfactory physio- 

 logical support (see chap, x-xii). These parts, particularly 

 the pars intermedia, are the least vascular of the whole pitui- 

 tary body, so that novel routes of conveying the secretion 

 (which is thought to be represented by "colloid" or "hyaline 

 material" [Herring, Gushing, Collin, and Roussy]) have been 

 postulated. Colloid accumulations in the pars intermedia or 

 hyaline material in the pars neuralis have also been consid- 

 ered to represent degenerative changes (Bailey, De Beer, and 

 others). Herring (1908, 1913, 191 5) believed that the colloid 

 (of the pars intermedia) and the hyaline material (as a holo- 

 crine secretion of the pars intermedia) found their way into 

 the pars neuralis whence, after storage with possible conver- 

 sion into more active substances, they ultimately passed 

 through the ependymal lining of the third ventricle into the 

 cerebrospinal fluid. This view in modified form is also held 

 by Collin, Roussy, Cushing, and others. A recent paper by 

 Cushing (1933) contains a restatement of his position. Other 

 reports are by Costa (1923, 1925), Collin and others (1924- 

 25, 1929, 1933-34), Florentin (1934), and Roussy and 



[32] 



