THE PITUITARY BODY. 417 



THE PINEAL GLAND. 



The pineal gland, or conarium, is a small body, about the 

 size of a pea, resting upon the nates and covered by the back 

 part of the corpus callosum. It consists of a fibrous capsule 

 and framework, lying in which are vesicles, cells, blood-ves- 

 sels, and sabulous matter. There is generally a cavity near the 

 base of the gland. 



The interior of the structure is divided into a cortical and 

 medullary portion. The former is composed of little vesicles, 

 resembling those of the pituitary body. The central portion 

 is filled with nerve-cells and sabulous matter, the latter lying 

 in the cavity at the base. The nerve-cells are of two kinds : 

 one, large, -fa mm. in diameter, and giving off long pro- 

 cesses ; the other, very small, ^ mm. in diameter, and giving 

 off processes, in the adult. Nerve-fibres run among these 

 cells, and connect them to the medullary substance of the 

 cerebral lobes and to the crura cerebri. They are considered, 

 by Meynert, to be ganglion-cells giving origin to fibres in the 

 crura cerebri. 



The sabulous matter is composed of corpora amylacea and 

 of earthy salts combined with animal matter. The earthy 

 salts are : phosphate and carbonate of lime, phosphate of am- 

 monia, and magnesia (Stromeyer). 



There is no doubt that the pineal gland contains consider- 

 able nervous tissue. It is not yet determined, however, whether 

 it should be considered a ganglionic centre or a structure of 

 similar character to the suprarenal capsules. 



THE PITUITARY BODY. 



The pituitary body (TiypopJiysis cerebri) is notable for the 

 peculiarity of its development and its uniform presence in all 

 vertebrates. It is a small, reddish gray, vascular mass, ovoid 

 in shape, and situated in the sella turcica. It is composed of 

 two lobes, anterior and posterior, the former being the larger. 

 In structure, the body, in its anterior lobe, has some resem- 

 blance to the suprarenal capsules, being composed of a con- 

 nective-tissue framework, in which lie blood-vessels and closed 

 vesicles. These latter consist of a homogeneous membrane en- 



