458 



Prof. E. A. Schafer. 



[July 22, 



and projected before attempting to decide whether pituitary feeding has the 

 distinct influence upon growth which might be inferred from this 

 experiment. 



Here the observations of Cerletti (1907) and of Sandri (1907) may be briefly 

 referred to. 



Cerletti injected young animals (intraperitoneally). As the result he found that the 

 bones of the animals receiving the pituitary emulsion were after some time, as compared 

 with controls, somewhat shorter as regards the diaphyses but larger as regards the 

 epiphyses. If Cerletti's results are to be accepted, they appear to indicate if anything 

 a retardation in growth of the bones, at any rate in the direction of length. Sandri fed 

 young mice with pituitary — apparently with the pure crude gland to the exclusion of 

 other food. He states that this caused an arrest of growth, but there seem to have been 

 no controls made with food of a similar percentage composition. Sandri also injected 

 young guinea-pigs with an emulsion of the gland, and found that in these also growth 

 was diminished. 



Our experiments have certainly not shown any arrest of growth as the result of 

 pituitary feeding. 



Grafting Experiments. 



Another method by which we are endeavouring to investigate the effects 

 of pituitary secretion upon growth is that of implanting pituitaries of other 

 individuals of the same species in various parts of the body, such as the 

 brain, the subcutaneous tissue, the muscular tissue, the peritoneal cavity, 

 and the kidneys. But so far these experiments have failed to throw any 

 clear light on the question by reason of the fact that we have not in 

 any case obtained a permanent graft of the implanted organ. The chief 

 result which has been noted is a temporary increase in the amount of urine 

 secreted, a result due either to absorption of the diuretic substance which 

 the transplanted pituitary contained, or, perhaps, to a temporary functioning 

 of the implanted organ preceding its degeneration. All the animals in 

 which this attempt to implant the pituitary has been made — including dogs, 

 cats, monkeys, and rats — have remained healthy and have been killed after 

 a certain lapse of time. In no case have we been able on post-mortem 

 examination to substantiate the presence of the characteristic epithelial 

 structure of the pituitary at the site of implantation. In one experiment, 

 which is still in progress and a chart of which is appended (fig. 4), the 

 animals (rats) with pituitary grafts grew at first at exactly the same rate 

 as the controls of the same litter and sex. But after three weeks the 

 controls for some unexplained reason lost weight for a few days, and have 

 hardly as yet managed to catch the others up. 



The chart of urine-secretion (fig. 5) follows almost exactly the same course 

 in the two groups : the effect of the implantation in these animals was 

 therefore to all appearance nil. 



