PATHOLOGICAL ANATOMY AND HISTOLOGY 267 



infections, slightly increased in arteriosclerosis and in various nephritides. 

 Their variations, however, are slight and as they place the normal content 

 lower than does Elliott (</) (2 mg. per gland) the relative content in the 

 latter conditions appears higher. Pfeiffer in his experimental studies has 

 shown also that the chromaphil tissues respond very quickly to toxic or 

 nervous influences. He notes complete absence of the chrom reaction in 

 seventy minutes to two and a half hours. On the other hand, he found 

 complete regeneration of the reaction in forty-eight hours. 



A necessary condition for the study of the chromaphil substance is 

 fixation in solution containing chrom salts and immersion in the fixative 

 not too many hours after death. Ciaccio(a) showed that the material dis- 

 appeared fairly rapidly as a result of postmortem change. It is question- 

 able therefore whether much reliance can be placed upon postmortem esti- 

 mates of the epinephrin on account of this rapid disappearance. It is prob- 

 ably influenced by agonal conditions also. 



Pfeiffer has made extensive experimental studies upon the variation 

 of the lipoid and the chromaphil substances in rabbits, guinea pigs and 

 rats as a result of different stimuli. In his experiments he used stimula- 

 tion of the splanchnic, piqure, the effect of removing both kidneys, the 

 action of light after injection of photodynamic substances and finally, the 

 effect of scalding. His conclusions have an interesting bearing upon the 

 phenomena of disappearance of lipoid and chromaphil material in cortex 

 and medulla. He regards these phenomena along with hyperemia as 

 evidence of functional overactivity. Functional activity of the glands 

 may be traced through all stages from the first induction of it to the end 

 stage in which complete exhaustion of lipoid and chromaphil substance is 

 attained. As a consequence of these observations Pfeiffer would hold 

 that it is wrong to speak of death as clue to acute suprarenal insufficiency. 

 In all cases the insufficiency is secondary to changes in the body generally, 

 and experimentally the condition is reversible, the lipoid and medullary 

 secretion can be restored. Only where pathological conditions in the body 

 lead to a persistent exhaustion of these substances can one speak of the 

 influences of suprarenal insufficiency. These changes occur equally in 

 cortex and medulla ; the organ reacts as a whole but Pfeiffer's experi- 

 ments show that the medullary function is the more labile, the cortical 

 the more stable. Disappearance of chrom reaction may occur without 

 evident diminution of lipoid, though where the stimulus is intense, the 

 cortical reaction rapidly sets in. This is in direct contradiction of 

 Landau's (b) view that the medullary reaction is always secondary to that 

 of the cortex and is conditioned by cortical changes. Pfeiffer's experi- 

 ments were carried out with the idea of proving that the suprarenal 

 exhaustion was due to proteose intoxication. In his series, he used not 

 only single animals, but animals parabiotically united, and in these para- 

 biotic animals, where acute damage was applied to one animal, if 



