26 ENDOCRINE THERAPEUTICS 



occur in the human, that is, if the proportions 

 remain like those of other animals, the brain fails 

 to develop properly, or an entirely brainless 

 monster is generated. The human brain, there- 

 fore, probably owes its superiority over the 

 animal brain to the adrenal cortex, in develop- 

 ment anyhow. The growth of the brain-cells, 

 their number and complexity, are thus controlled 

 by the adrenal cortex." 



The medulla contains and secretes adrenalin, a 

 substance that has also been made synthetically. 

 If the gland is hardened in a chromate solution, 

 the medulla stains brown the chromate com- 

 bining with the adrenalin ; thus arises the name 

 chromaffine. There are other small scattered 

 groups of chromaffine cells that are found along 

 the course of the large abdominal blood-vessels. 

 The duration of life varies in animals after 

 removal of the gland ; this is probably due to the 

 varying number of these accessory portions. 



Adrenalin is not found in the cortex. Bain- 

 bridge says : " When a small amount of adrenalin 

 is injected into a blood-vessel, it produces con- 

 striction of almost all the arterioles of the body, 

 and, if the vagus nerves have been divided, an 

 enormous rise of blood- pressure is produced. 



