THE ADRENAL BODIES 233 



query above, as to why the presence of intact nerves should 

 interfere with the response to the chemical agent. 



In regard to the effects of asphyxia, our results differ from 

 those of Anrep. We have been unable to obtain tracings 

 showing any significant difference in the behaviour of a dener- 

 vated limb during asphyxia in an animal with adrenals sup- 

 pressed as compared with one in a normal animal. 



It seems impossible to avoid the conclusion that when power- 

 ful impulses are transmitted along certain afferent or efferent 

 paths, the adrenal bodies (or, more correctly, the masses of 

 chromaphil tissue contained within these bodies) play a part 

 in the total response. Whether, under normal condition of the 

 animal, the impulses which are so transmitted are sufficiently 

 powerful to give rise to results similar to those of the laboratory 

 experiments, or whether they are of such a character as to be 

 adequate for such results, we cannot pretend to say. It is 

 tempting to assume that the impulses may become adequate 

 in physiological emergencies, as was suggested by Cannon and 

 de la Paz. 



It appears from our own tracings and from those of Elliott 

 that, although the character of the splanchnic curve is seriously 

 modified by elimination of the adrenals, the total rise of blood- 

 pressure may not be affected, or may even be greater than 

 before. It follows that in these cases the effect of the adrenin 

 actually poured out into the circulation is a fall of blood- 

 pressure and not a rise. This corresponds with the fact that 

 small doses of adrenin produce a fall and not a rise. In other 

 cases, however, the total rise is greater in the intact animal. 



The question arises as to the nature of the process by which 

 the adrenin is poured out into the circulation in sufficient 

 quantity to produce, in laboratory experiments, the effects 

 detailed above. It is generally assumed that the process is a 

 true secretion, and that the splanchnic nerve is the channel 

 along which the secretory fibres run. This is supposed to apply 

 equally to experiments in which the splanchnic itself is stimu- 

 lated and in those in which changes in the circulation are 

 brought about reflexly by stimulation of different afferent 

 nerves. 



Some observers have alleged that the discharge of adrenin 

 is the result of vaso- dilation of the adrenal body as a result of 

 direct or reflex stimulation of its vaso-motor nerves. It would 



