REMOVAL OF THE SUPRARENALS 75 



at the expense of the zona reticularis and medulla. My Hypertrophy 

 own observations are in accord with this. The zona 

 reticularis does not increase at the expense of the zona 

 fasciculata in pregnancy, as it does after oophorectomy. 

 Conflicting views as to the effects of castration have 

 been put forward by Schenk 1 , Cecca 2 and others, A 

 source of error in the estimation of the thickness of the 

 various zones is liable to arise unless care be taken to 

 cut mesial sections, or, better still, serial sections. 



EFFECTS OF THE REMOVAL OF THE SUPRARENALS 



In most mammals complete removal of the supra- Effects of 

 renals causes death in from a few hours to a few days, 

 The animal does not eat ; it sits very quietly and gradu- 

 ally becomes weaker ; tremors occur, and death super- 

 venes. This sequence of events follows so rapidly that 

 as a rule no estimation can be made of the metabolism, 

 and any changes observable in other hormonopoietic 

 glands must be of an acute character, and therefore of 

 less value from a practical point of view than those 

 which are obtained by the production of chronic in- 

 sufficiency a condition difficult to bring about experi- 

 mentally in the suprarenals. Acute effects may, however, 

 be useful as indicating the trend of physiological events. 



Many rats, owing to the fact that a large percentage 

 of them have accessory interrenals consisting of cortical 

 substance, are said to be able to survive extirpation of 

 the main organs. It is, therefore, believed that the 

 cortical part alone is necessary to life ; and this belief 

 is supported by other evidence which has recently been 

 discussed by Vincent 3 . 



My investigations were carried out with rabbits and Author's 

 cats. Those animals from which both suprarenals were experiments. 

 removed, either at one or at two sittings, died within 



1 Schenk, F., Archiv. f. Exper. Pathol u. Pharmacol., 1910-11, 

 vol. Ixiv, p. 362. 



2 Cecca, R., Presse Mtdicale, 1904, vol. xii, p. 341. 



3 Vincent, S., Endocrinology, 1917, voL i, p. 140. 



