i INTERNAL PEOTECTIVE SECRETIONS 41 



Osborne and Vincent, on the contrary, that it has a depressing 

 action ; Howell (1897), that it retards arid reinforces the pulse ; 

 according to Cyon, lastly, it contains two active substances, the 

 one retarding, and the other accelerating, the pulse. 



Cyon thought he had demonstrated that the hypophysis 

 regulates endocranial pressure, slowing and strengthening the 

 pulse, and reducing blood pressure, by the fact that its direct 

 stim-ulation by gentle mechanical compression and weak electrical 

 currents, produced these effects. It is difficult to determine 

 exactly how much of this interpretation can be accepted. The 

 situation of the pituitary body justifies the assumption that its 

 excitatory impulses are transmitted by the lobule of the infundi- 

 bulum to the cardiac centres of the vagus. If this be so, it plays 

 no part in the production of the phenomena described. 



Gaglio, moreover, found that in frogs operated on by hypo- 

 physectomy, the bulbar centres of the vagus are as excitable to 

 increased blood pressure, not only days and weeks, but also a few 

 hours, after the operation, as in normal frogs. This does not agree 

 with Cyon's observations on rabbits. 



Nor has clinical observation thrown more light on the functions 

 of the hypophysis. Since Marie and Marinesco (1891) suggested 

 that acromegaly was the expression of a systematic dystrophy, 

 consequent on functional disturbance of the pituitary body, many 

 new facts have militated against their theory. Collina (1898) 

 diligently collected all cases of this disease in which there had 

 been a post mortem. He found that in a large majority the tumour 

 was represented by adenomata and sarcomata. On the other hand, 

 as was observed by Strunipell (1897), hypophysal tumour is not 

 invariably present in acromegaly, while such a tumour often 

 occurs without acromegaly. As regards organo-therapy, Mendel 

 and Marinesco (1895) noticed improvement with pituitary ex- 

 tract ; Schultze, on the contrary (1897), denied that it had any 

 beneficial action. 



The function of the hypophysis is therefore wholly un- 

 determined, and it may be stated in conclusion that of the 

 various far-fetched and improbable theories, that proposed by 

 Rogowitsch as above appears least hazardous, although it has 

 not been demonstrated. 



Among the more recently acquired experimental data the 

 following should be noted. 



Guerrini (1904) found, by a series of microscopic researches 

 on various animals, that the pituitary body, in every alteration 

 of metabolism due to endogenous or exogenous intoxication, 

 exhibits phenomena of functional irritation analogous to those 

 shown in other glandular organs; if protracted, these may lead 

 to hypertrophy and hyperplasia of the parenchyma of the gland. 



Fichera (1905) in a first series of experiments (macroscopic 



