340 THE DUCTLESS GLANDS 



Besides the colloid, it is probable that there are other 

 secretory products. 



In no other endocrine gland are the granular products of 

 secretion so well seen as in the anterior lobe of the pituitary 

 body. Secretory granules are also seen in the vessels belonging 

 to the gland. 



Leyton, as a result of, the examination of a large number 

 of human pituitaries, came to the conclusion that colloid 

 material may be found in the bloodvessels, both in the an- 

 terior lobe and also in the so-called pars intermedia. Colloid 

 material was not seen in the pars nervosa. 



In children and in the foetus the distinction between the 

 different varieties of cells in the anterior lobe is not marked, 

 and colloid material is small in amount. 



Stalk of pituitary 

 Infundibular cavity 



Cleft in pars 

 intermedia 



FIG. 94. Diagram showing relations of principal parts of pituitary body. 



The size and weight of the gland and the amount of colloid 

 material are subject to very great variation. 



Gushing and Goetsch find colloid masses in the posterior 

 lobe of the pituitary, and agree with Herring that the colloid 

 masses in this lobe are secretory products of the epithelial 

 covering of the pars intermedia. They find in the cerebro- 

 spinal fluid a substance which gives the same reactions as 

 the pars nervosa itself. 



The intermediate portion consists of finely granular cells 



