726 DEAN LEWIS 



trols being given meat. He believed that the animals fed the anterior lobe 

 gained more weight than the controls but the figures indicate that the 

 gains were* so slight that they could scarcely be regarded as significant. 

 The controls gained during the two months, on an average, 10 gm. ; 

 those fed on the posterior lobe Y gm. and those fed on the anterior lobe 12 

 gm. Variations of this amount may occur in any series of feeding experi- 

 ments continued over this period. 



In Schaefer's feeding experiments, four young rats were fed small 

 amounts of the dried anterior lobe mixed with bread and milk, while 

 the controls were fed powdered testicle or ovary with bread and milk. 

 The amounts consumed by each group of rats were accurately determined. 

 The experiments were carried through a period of three months. At the 

 beginning, the average weight of the group fed upon the hypophysis was 

 44.25 gm. ; that of the controls was the same. At the end of the experi- 

 ment the average weight of the rats fed on the hypophysis was 150 gm., 

 that of the controls 131 gm. During the first six weeks of this feeding 

 experiment litle difference between the two groups was noted, but during 

 the last six weeks those fed on the hypophysis made the more rapid 

 gain. 



Lewis and Miller in 1912 undertook feeding experiments with the 

 view of observing several series of animals with controls. Young rats were 

 selected for the experiments and each one was placed in an individual 

 cage. Fresh ox hypophyses were used for feeding; the anterior and 

 posterior lobes were separated, chopped up and dried in a blower at a 

 temperature of approximately 100 F. The dried glands were then 

 powdered and a weighed amount added to powdered cracker, the mixture 

 being pressed into a tablet. It was then determined how much of this 

 food each rat would consume daily. 



There were some individual differences but it was possible with reason- 

 able accuracy to determine the daily ration. Cracker tablets of the 

 desired weight were prepared and to each was added a weighed amount of 

 the hypophysis or, in case of the controls, of meat. Each animal received 

 the same amount daily. Occasionally a rat might not eat the whole tablet, 

 but a note was made of this. The ration was with rare exceptions con- 

 sumed daily. The rats gained in weight and appeared healthy, indicating 

 that they were properly fed. Three series of animals were fed in this 

 way for about three months. At the end of this time they were killed 

 and examined. Radiograms were taken to determine whether or not there 

 were any bony changes. 



The first series consisted of nine rats. Three received daily 2 gm. of 

 dried anterior lobe; three the same amount of posterior lobe, and the three 

 controls the same amount of meat. 



The second series consisted of 8 rats. Four were fed 4 gm. of the 



