EDUARD UHLENHUTH 



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nately both of the controls were lost before the anterior lobe-fed ani- 

 mals had reached such an extraordinary size, but from our experiences 

 with many other animals as well as from the maximum size of this 

 species it is safe to conclude that the growth of the controls in this 

 experiment was nearly completed. On the other hand, the size of the 

 anterior lobe-fed animals exceeded the normal maximum size of the 

 species so much as to leave no doubt that both of them were giants. 

 The size of the larger experimental giant exceeded the size of the 

 largest normal animal of this species on record by 20 mm., and the 

 size of the smaller experimental giant exceeded the largest normal 

 animal on record by 12 mm. It is certain that both animals would 

 have become still larger had they survived, since they were still grow- 

 ing before they died. 



TABLE II. 

 Hypophysis-Fed Amby stoma tigrinum, Experiment 2. 



Similar results were obtained when metamorphosed specimens of 

 the species Amhystoma tigrinum were fed on anterior lobe. 



Experiment 2. — Five larvae (Series XL VI) were reared from eggs of 

 the same female and fed on earthworms. At the end of the second 

 growth period, about 24 weeks after metamorphosis, when the ani- 

 mals were 37 weeks old, three of them, among them the largest one 

 of the series, were kept on earthworms, while two, among them the 

 smallest one, were started on an exclusive diet of anterior lobe (for 

 initial sizes see Table II). 



Although the control animals were fed on an abundant supply of 

 earthworms, their rate of growth remained low as compared with 

 that during the second period of growth. The animals fed on anterior 



