156 SECTIONAL ADDRESSES 
CONCLUSION. 
The pituitary body is anatomically and physiologically bound up with 
the diencephalon in all vertebrates from the earliest stages of development. 
The diencephalon itself is the site of integration of nerve impulses con- 
cerned in the regulation of many of the fundamental processes of life. 
It possesses a diversity of structures, not the least important of which is 
that derived from the buccal mucous membrane, the epithelial elements 
of the pituitary body. The pituitary body provides the brain with an 
armamentarium of hormones. Some of these exert their actions directly 
upon peripheral tissues through the blood stream ; others act locally upon 
nervous mechanisms in the hypothalamus. All are under the control of 
this part of the brain. 
The diencephalon and pituitary body form a working unit, and have 
functions of far-reaching importance in the control of fundamental 
physiological processes. It is probable that the pineal body is another 
part of the same mechanism, but its functions are still to be discovered. 
