722 DEAN LEWIS 



gland. The technic was not refined and many of the results were un- 

 doubtedly flue to infections or injuries of the brain. As the operations 

 were often done through a small incision it was correspondingly difficult 

 to determine whether the gland was partially or completely removed. 



Paulesco(a) (1906) employed the lateral or temporal route for expo- 

 sure of the hypophysis. In this operation the gland may be exposed so well 

 that one or the other lobe may be removed, or the stalk divided as 

 desired. It should be remembered, however, that even after total 

 hypophysectomy the portion of the pars intermedia, which is reflected onto 

 the floor of the third ventricle the so-called pars tuberalis is left behind. 



Paulesco attempted total hypophysectomy upon 22 dogs and cats. 

 Ten of the animals died within 48 hours following the operation. No 

 adequate cause of death was found at autopsy in these cases for there was 

 no evidence of infection. The investigator concluded, therefore, that the 

 death of these animals must have been caused by the loss of hypophyseal 

 secretion. In 14 animals the hypophysectomy was not complete, for at 

 the autopsy remnants of the hypophysis of varying sizes were found. If 

 the pieces of the hypophysis which had been left were small the animal 

 survived but a few days (3-10) ; but those animals in which larger pieces 

 had been left lived some time, one as long as 395 days. 



Even almost total destruction or removal of the hypophysis seemed 

 not to give rise to any particular group of symptoms or trophic dis- 

 turbances. 



In seven animals a total destruction of the cortical substance of the 

 anterior lobe was caused by a thermocautery. These animals died shortly 

 after the operation ; the destruction of the cortical portion of the anterior 

 lobe is the equivalent of total hypophysectomy as far as the life of the 

 animal is concerned. 



In three animals partial destruction of the anterior lobe was per- 

 formed. These animals lived respectively 23, 36 and 132 days without 

 developing any noticeable symptoms. 



The posterior lobe was removed in five animals, one of which lived 

 two years after the operation and then died of some intercurrent disease. 

 Removal of the posterior lobe seemed to have no especial effect upon the 

 animal, but separation of the stalk was followed by death, stalk separation 

 being the equivalent of total hypophysectomy. 



It is a little difficult to reconcile these last findings for posterior lobe 

 removal would seem to be almost the equivalent of stalk separation. In 

 stalk separation the operative procedure is carried up near the floor of the 

 third ventricle, but opening of the third ventricle or injury of the same, 

 the experiment having been performed as control, does not have the 

 effect ascribed by Paulesco to stalk separation. It is quite possible that in 

 stalk separation some of the vessels supplying the anterior lobe are injured 



