Growth and Metamorphosis of Tadpoles. 



297 



(5) The fats to be tested were added (either alone or after admixture 

 with known quantities of iodine) to the basal diet in the proportion of 

 approximately 1 grm. of the fat to 1 grm. of the flour-easeinogen 

 mixture. A dough of soft consistency was prepared therefrom, and the 

 mass divided into a number of small pills which were supplied to the 

 tadpoles. 



(6) In the first series of eight dishes the effects of the various fats, as 

 compared with controls receiving the same basal diet but without fats, were 

 observed (fig. 1). 



Fig. 1.— Showing the effects on growth of tadpoles of an excess of oleic acid, of butter, and of 



cod-liver oil in the food. 



(7) In the second series of eight dishes the effects of the various fats after 

 admixture with iodine, in the proportion of 0-5 mgrm. per gramme of food- 

 mixture, were observed in contrast with controls receiving the same amount 

 of iodine in the basal diet but without fats (figs. 2, 3, 4). 



(8) In the third series of eight dishes the effects of the various fats after 

 admixture with iodine, in the proportion of 1 mgrm. per gramme of food- 



