THE SUPRARENAL CAPSULE 581 



moval of all the parathyroids proves fatal within a short time, 

 even if the thyroid gland be left intact ; the animal dies from 

 " tetany " ; excision of the thyroid gland, on the other hand, 

 causes " cachexia strumipriva " or " post-operative myxcedema " ; 

 previous experimenters had removed both glands, and hence the 

 results were of a mixed character. Cretinism and myxcedema are 

 due to insufficiency of the thyroid gland, and exophthalmic goitre 

 may be accompanied by disease of the parathyroid glands. 



The results, however, are very discordant, and do not bear out 

 the view that the thyroid gland is less important than the para- 

 thyroid ; the glands are often so closely associated that it is 

 extremely difficult or even impossible to remove the one without 

 serious damage to the other. Further research, especially upon the 

 comparative physiology of the glands, must decide their relative 

 importance. 



THE SUPRAEENAL CAPSULE 



The suprarenal capsule is a ductless gland, the functions of 

 which were entirely unknown until fifty years ago, when Addison 

 published his account of the peculiar disease which is now known 

 by his name. This clinical work was quickly followed by the 

 researches of Brown-Sequard upon the effects of removal of the 

 glands, and his results showed that the suprarenal bodies, far from 

 being the foetal relics which they were once thought to be, were 

 absolutely essential for life. The idea that the capsules were mere 

 foetal relics appears to have arisen from a comparison of the 

 relative size of the gland in the foetus and the adult. At the 

 third month of intrauterine life the kidneys and suprarenal 

 capsules are of the same size ; at the sixth month the kidneys 

 are twice the size of the capsules ; the glands continue to grow 

 after birth, and in the adult man each suprarenal body weighs 

 about 4 grm., each kidney about 156 grm. 



Accessory suprarenal bodies are often found in the connective 

 tissue in the neighbourhood of the kidneys, and this fact offers a 

 sufficient explanation of the negative results obtained by some 

 observers, who have removed the suprarenal capsules. The de- 

 velopment of the gland shows that it has a twofold origin, corre- 

 sponding to the cortex and the medulla ; the former part appears 

 to arise from the epithelium of the coelom in the Wolffian ridge, 



