I.—PHYSIOLOGY 149 
puncture of the third ventricle, or injury to various parts of the hypo- 
thalamus, are almost as effective as the Bernard piqtre. Stimulation of 
the exposed pituitary body gives a similar result. Cushing believes that 
the glycosuria resulting from the Bernard piqtire may be explained by the 
injury of descending nerve fibres from the hypothalamus lying super- 
ficially in the middle line of the floor of the fourth ventricle. Karplus and 
Kreid! showed that in cats stimulation of the hypothalamus lateral to the 
infundibulum produces dilatation of the pupil, separation of the eyelids 
and retraction of the nictitating membrane. ‘They also obtained profuse 
sweating of the feet and a rise of arterial pressure, all dependent upon an 
intact sympathetic system. Houssay and Molinelli in 1926 stated that 
weak stimulation of the hypothalamus gives rise to a considerable increase 
in the secretion of adrenaline. Beattie, Brow and Long have shown 
that the posterior part of the hypothalamus is the portion related to 
the sympathetic system. Its stimulation produces the secretion of 
adrenaline. Beattie states there are probably two distinct mechanisms 
in the hypothalamus, an anterior or parasympathetic, and a posterior 
or sympathetic. There is further evidence for the location of a higher 
co-ordinative sympathetic mechanism in the posterior part of the hypo- 
thalamus. Bard has shown by serial sectioning of the brain in living 
cats that the condition, designated by Cannon ‘ sham rage,’ occurs after 
ablation of cortex, corpora striata and the cranial half of the diencephalon, 
and disappears when a section is made between the diencephalon and the 
mid-brain. The phenomena of sham rage are largely those of intense 
stimulation of the sympathetic system. The diencephalon is one of the 
oldest portions of the brain, and the hypothalamus exists throughout the 
vertebrate series. Rioch, in a study of this region in carnivora, finds 
evidence of a general pattern in its nuclei and tracts. Eaves and Croll 
have shown that the grey matter of the hypothalamus is more severely 
affected in chronic epidemic encephalitis in the human subject than any 
other part of the brain with the possible exception of the substantia nigra, 
and that the pituitary body is frequently involved in the lesions. 
Evidence is accumulating that the hypothalamus is an important, if not 
the main, site of integration of the basic activities which are common to 
the life of all vertebrates. The metabolism of solids and of water, with 
its accompaniments of hunger and thirst, the regulation of body tempera- 
ture, emotional reactions, sleep, mating and reproduction, may have an 
anatomical basis in this part of the brain. The pituitary body is an 
essential part of the mechanism whereby the hypothalamus is enabled to 
carry out and control its vital activities. 
HORMONES OF THE PITUITARY. 
Many hormones are now allocated to the pituitary body, and more may 
be discovered. It is as yet impossible to say that the numerous prepara- 
tions which have been made represent substances actually secreted by 
the gland, and until the hormones can be isolated in a pure state we cannot 
be certain of their properties. ‘The hormones of the anterior lobe are 
carried by the blood to all parts of the body, and their ultimate effects 
are complicated by the enhancement or otherwise of the internal secretions 
