802 PHYSIOLOGY OF DIGESTION AND SECRETION. 



others have shown that extracts of the hypophysis when injected 

 intravenously have little or no physiological effect, while extracts 

 of the infundibular body, on the contrary, cause a marked rise of 

 blopd-pressure and slowing of the heart beat. These effects resemble 

 in general those obtained from adrenal extracts, but differ in some 

 details. They seem to warrant the conclusion that the infundib- 

 ular body is not a mere rudimentary organ, as had been generally 

 assumed, but produces a peculiar substance, an internal secretion, 

 that may have a distinct physiological value. The most signifi- 

 cant observation made in regard to the probable functional signifi- 

 cance of the internal secretion of the infundibular lobe is found 

 in the experiments of Schafer and Herring.* These observers 

 report that this part of the gland yields a substance soluble in 

 water and not destroyed by boiling, which acts specifically upon the 

 kidney, producing a dilatation of the renal vessels and an increased 

 secretion of urine. A number of observers, especially Vassale and 

 Sacchi, have succeeded in removing the entire pituitary body. 

 They report that the operation results eventually in the death of 

 the animal with a certain group of symptoms, such as muscular 

 tremors and spasms, apathy and dyspnea, that resemble the results 

 of thyroidectomy. It has been suggested, therefore, that the pit- 

 uitary body may be related in function to the thyroids and may be 

 able to assume vicariously the functions of the latter after thy- 

 roidectomy. There is no satisfactory evidence, however, in support 

 of this view. On the pathological side it has been shown that 

 usually lesions of the pituitary body, particularly of the hypophysis,- 

 are associated with a peculiar disease known as acromegaly, the 

 most prominent symptom of which is a marked hypertrophy of the 

 bones of the extremities and of the face. The conclusion sometimes 

 drawn from this fact that acromegaly is caused by a disturbance 

 of the functions of the pituitary body is, however, very uncertain, 

 and is not supported by any definite clinical or experimental facts. 



Organs of Reproduction. Some of the earliest work upon the 

 effect of the internal secretions of the glands was done upon the 

 reproductive glands, especially the testis, by Brown-Sequard.f Ac- 

 cording to this observer, extracts of the fresh testis when injected 

 under the skin or into the blood may have a remarkable influence 

 upon the nervous system. Mental and physical vigor, and the 

 activity of the spinal centers, are greatly improved, not only 

 in cases of general prostration and neurasthenia, but also in the 

 case of the aged. Brown-Sequard maintained that this general 

 dynamogenic effect is due to some unknown substance formed 

 in the testis and subsequently passed into the blood, although he 



* Schiifer and Herring, "Philosophical Transactions, Royal Society," 

 London, 1906, B. cxcix., 1. 



f " Archives de physiologic normale et pathologique, 1889-92. 



