THE SUPRARENAL SYSTEM 145 



the products of secretion, were not present in the medullary cells. 

 With the exception of moderate enlargement of the vessels, the 

 cortical substance presented no signs except those of an increased 

 secretory activity. 



L. della Vida employed immune serums obtained separately 

 from the cortex and medulla of the suprarenals of guinea-pigs. 

 He states that the action of the medulla-serum was toxic to his 

 animals and produced hyperaemia of all the organs, together 

 with degenerative changes in the suprarenals, kidneys, and liver. 

 It is more than probable that the cytotoxic sera employed by 

 della Vida were strictly specific in vitro, but that at the same time 

 they were more or less haemolytic in their activity ; this renders 

 it difficult to distinguish the toxic effects of the haemolysis from 

 any specific disturbances which may have taken place in the 

 suprarenal tissue. 



From the results which have been obtained by extirpation of 

 the suprarenals the following conclusions may be drawn :- 



(1) From the fact that it is followed by no pathological signs, 

 the removal of one suprarenal must be regarded as negative in 

 its effect upon the organism. The compensatory hypertrophy 

 which invariably takes place in the remaining organ and in any 

 accessory organs which may be present, shows that this negative 

 effect is not due to an absence of functional significance, but to 

 the fact that the suppressed function is replaced by the vicarious 

 activity of the remaining organ and of other similar tissues. This 

 hyperfunction is expressed anatomically by hypertrophy. 



(2) Extirpation of both suprarenals is as a rule followed by 

 the death of the animal, whatever its species, within a very short 

 space of time (hours or a few days). That this is not due to the 

 severity of the operation or to secondary causes, such as infection, 

 &c., but occurs solely as a result of the suppression of the func- 

 tion of the organs, is shown by the constancy of the result ; for 

 death follows even in those cases where, the organs having been 

 previously dislodged, the operation is a slight one. It is evident 

 then, that the suprarenals are not only important to life, but that 

 they" are essential to it. 



(3) Whether the suprarenals are removed together or singly, 

 with a longer or shorter interval between the operations, the final 

 result of complete epinephrectomy will be the same. But where 

 both the organs are removed at once, the duration of life is much 

 shorter, and it would appear from this that the sudden suppression 

 of the suprarenal function is not compatible with a continuation 

 of life. That the duration of life is longer where the suprarenals 

 are removed separately is explained by the fact that, in the 

 interval, any accessory suprarenal tissue which may be present 

 undergoes compensatory hypertrophy and, after removal of the 

 second suprarenal, does what it can to replace the suppressed 

 function, though necessarily to an insufficient extent. 



10 



