Dietary Deficiencies on the Suprarenal Glands. 



17 



It is evident that this dose of "marmite," when added to a diet of 

 polished rice and oil, though it prevents the onset of symptoms and the 

 enlargement of the suprarenals, is not enough to prevent some increase in 

 the amount of adrenaline. The deficiency of fat in a dietary of polished rice 

 has obviously no causal relation either to the hypertrophy of the adrenals or 

 to increase in the content of adrenaline produced by feeding with such 

 a diet. 



The Effect of the Addition of a Fat Rich in Fat Soluble A, to the Diet of 



Polished Bice. 



Although there is no evidence that fat soluble, A, is a necessary constituent 

 of the normal diet of pigeons, the effect of the addition to the diet of 

 polished rice of cod liver oil, a fat rich in this accessory factor, was 

 investigated. Series 10 (Table VI) gives the results obtained. 



Four out of the five birds in this series were killed on the twentieth day 

 without having exhibited any symptoms of polyneuritis, though they showed 

 some fall of body weight ; there was no lowering of their cloacal tem- 

 perature, and they were indistinguishable from normal birds. One was kept 

 on the diet till the thirty-fifth day, and was then at the point of death, with 

 extremely low cloacal temperature, great weakness and wasting, but with no 

 definite symptoms of polyneuritis. This bird had been emptying its crop 

 shortly after feeding, a tendency which was marked in all the birds of this 

 group. 



These pigeons had been caged for a month before the experiment was 

 started, and the figures for weight of adrenals and of adrenaline per kilo- 

 gramme of original body weight, i.e., 103"3 mgrm. and 0"438 mgrm., may be 

 compared with those of normal birds kept the same time under identical 

 conditions, i.e., 60*9 mgrm. and 0-255 mgrm. (Table II). 



This experiment is complicated by inanition, which McCarrison (1919, a) 

 has shown to cause both the suprarenal effects under investigation, but 

 affords no evidence that fat associated with fat soluble A, behaves at all 

 differently from fat free from accessory substances, so far as these suprarenal 

 changes are concerned. It seems possible that the absence of definite 

 symptoms of polyneuritis from these birds may be due to the presence of a 

 trace of water soluble accessory factor in the daily ration of cod liver oil. 



The Effect of the Addition to the Diet of Protein free from Vitamines 



and Fat. 



The protein used for this purpose was commercial casein, which, after a 

 jneliminary extraction with cold ether, was repeatedly extracted under a 

 VOL. xcii, — B. ' c 



