NERVOUS AND ENDOCRINE CONTROL 1 47 



overactivity does not appear until maturity a different type of enlarge- 

 ment takes place in certain bones, notably those of the hands and feet, and 

 the cheekbones, jawbone and the bony ridges over the eyes, so that condi- 

 tion of deformity known as acromegaly results. On the other hand, the 

 well-proportioned, intelligent midget is commonly the subject of anterior 

 pituitary insufficiency. Such pituitary dwarfism in man can be success- 

 fully treated with anterior lobe extract provided it is administered before 

 the closure of the growth zones of the long bones which follows the ad- 

 vent of the adult sex hormones. This type of dwarfism is apparently un- 

 related to that caused by thyroid deficiency, since thyroxin will not cor- 

 rect it. 



Repeated transplants of anterior lobe substance induce precocious sexual 

 maturity and ovarian growth. Young mice which ordinarily become 

 sexually mature at the age of about thirty-five days, following such treat- 

 ment may become fully mature by the end of twenty-one days. Biologists 

 at the University of Wisconsin have made practical use of this gonad- 

 stimulating property of anterior lobe material by using it to speed up 

 spawning in various fish. They were able thus to spawn rainbow trout 

 two months in advance of the normal time and so gain a longer growth 

 period of the young fry before transplantation from hatchery to stream. 

 What was more important, however, they showed that highly prized 

 game fish which have hitherto proved refractory to artificial spawning, 

 such as bass and muskellunge, can be made to spawn freely by such in- 

 jections. It thus becomes practicable to grow the young of such fish in 

 hatcheries for a time for later use in replenishment of fished-out waters. 



The adrenal glands, as the name impHes, are associated with the kidneys. 

 Each gland is a double structure, consisting of a core or medullary por- 

 tion which is derived from the adjacent sympathetic nervous system, and 

 an enveloping cortical portion originating from the lining of the body 

 cavity. The secretions from the two parts differ in physiological action. 



The secretion from the medullary portion called adrenalin, has not only 

 been isolated in a pure state but has also been synthesized in the laboratory 

 and is widely used as a drug. 



Adrenahn is used medicinally to relieve bronchial spasms in asthma, and 

 in conjunction with local anesthetics, for constricting blood vessels and 

 thus preventing rapid diffusion of the injected substance. It is also occa- 

 sionally used in attacks of hives or of hay fever. Introduced directly into 

 the heart tissue in certain cases of collapse, it will sometimes initiate re- 

 newed contraction in a heart that has ceased to beat. It is also employed 

 to induce temporary elevation of blood pressure following collapse of 

 the circulatory system during surgical operations. 



Professor Cannon and his associates concluded from their experiments 

 that under stress of such emotional states as pain, suffocation, fear or rage, 



