364: SECRETION. 



the most interesting points in its anatomical history relates 

 to its mode of development. This, however, does not pre- 

 sent any great physiological importance, and is fully treated 

 of in works upon anatomy. 1 



Pituitary Body and Pineal Gland. 



These little bodies, situated at the base of the brain, are 

 quite vascular, contain closed vesicles and but few nervous 

 elements, and are sometimes classed with the ductless glands. 

 Physiologists have no idea of their function. 



The pituitary body is of an ovoid form, a reddish-gray 

 color, weighs from five to ten grains, and is situated in the 

 sella turcica of the sphenoid bone. It is said to be larger in 

 the foetus than in the adult, and at that time has a cavity 

 communicating with the third ventricle. 8 Ecker describes it 

 as containing the elements of a blood-gland. 3 This little body 

 has lately been studied by M. Gran dry, in connection with 

 the suprarenal capsules. He regards it as essentially com- 

 posed of closed vesicles, with fibres of connective tissue and 

 blood-vessels. The vesicles measure from -g^-g- to y^-g- of an 

 inch in diameter. They are formed of a transparent mem- 

 brane, containing irregularly polygonal, nucleated cells, and 

 free nuclei. The cells are from ^^ to yyVg- of an inch in 

 diameter. The nuclei are distinct, with a well-marked nu- 

 cleolus, and measure about -g-jnnj- of an inch. Capillary ves- 

 sels surround these vesicles, without penetrating them. M. 

 Grandry did not observe either nerve-cells or fibres between 

 the vesicles. 4 In old subjects he found the peculiar concre- 



1 For the history of the development of the thymus, the reader is referred 

 to special treatises. A very full account of its development is given by Dr. 

 Handfield Jones, in the Cyclopaedia of Anatomy and Physiology, London, 1849- 

 1852, vol. iv., Part ii., p. 1087, et seq. 



2 GRAY, Anatomy, Descriptive and Surgical, Philadelphia, 1862, p. 519. 



3 ECKER, in WAGNER, Handworterbuch der Physiologic, Braunschweig, 1853, 

 Bd. iv., S. 161. 



4 GRANDRY, Glande pituitaire. Journal de V anatomic, Paris, 1867, tome iv., 

 p. 400, et seq. 



