MAMMALIA— PHYSIOLOGY . 447 



metabolism and shell formation in the birds. Crew reported (1928) 

 that removal of the thymus had no effect on calcium metabolism 

 in fowls. 



Snp7'arenals. — It has long been known that the suprarenal 

 glands are essential to life. The suprarenal medulla is the source 

 of epinephrin (adrenalin) which was the first hormone to be isolated 

 chemically (Takamine) and is extremely potent, one part in eight 

 billion producing reaction in the rabbit intestine. Wheeler and 

 Vincent found that as long as an adequate amount of cortex sur- 

 vived, destruction of all of the medullary tissue led to no ill effects. 

 Addison's disease is caused by pathological changes in the cortex 

 and is characterized by reduced blood sugar, subnormal temperature 

 and a peculiar pigmentation of the skin, with muscular weakness. 



In October, 1927, Rogoff and Stewart described the results 

 obtained with 0.9 per cent NaCl or glycerol extract of the cortex. 

 They treated completely adrenalectomized dogs. Of thirty dogs 

 treated, six lived longer than the longest of the control animals. 

 They did not give the average survival of treated animals as com- 

 pared with controls, which should have been done. In the same 

 month, 1927, Hartman, MacArthur and Hartman described the 

 first method for preparing an epinephrin-free extract of the adrenal 

 cortex. By the use of such an extract, the average survival period 

 of completely adrenalectomized cats was markedly increased (21 

 days) over that of controls (6 days). This average included all 

 cats treated, even those complicated by infections. 



In March, 1930, Swingle and Pfiffner described a method of 

 preparing a concentrated extract of the adrenal cortex sufficiently 

 potent to maintain the lives of adrenalectomized cats indefinitely. 

 Their process was very complicated and their extract contained 

 much epinephrin and inert material. In June, 1930, Hartman and 

 Brownell described a much simpler method of preparing a concen- 

 trated extract of the adrenal cortex containing less than i : 100,000 

 epinephrin. With this extract it is possible to maintain the lives 

 of adrenalectomized cats indefinitely. One animal was kept alive 

 for 268 days, dying because the extract was discontinued. This 

 substance, found in the adrenal cortex, which is essential to life, 

 has been called cortin. Both Swingle and Hartman have furnished 

 extracts to clinicians who have successfully treated cases of Addi- 

 son's disease with them. 



Suprarenal virilism is found in some women with diseased 



