Dietary Deficiencies on the Suprarenal Glands. 



7 



beri-beri. In certain later experiments on pigeons fed on polished rice with 

 the addition of butter and onions, he found that the polyneuritis, which was 

 quickly produced on this diet, was only rarely accompanied by oedema. 



There were several points in McCarrison's suggestive observations which 

 seemed worthy of further investigation. In the first place it was not clear 

 whether the effect of an exclusive diet of polished rice on the adrenals of 

 pigeons was due to specific deficiency of the accessary factors concerned with 

 the development of polyneuritis, or to the more general deficiency of protein, 

 fat or salts entailed by such a diet. In the second place, assuming the effect 

 to be a specific one, and McCarrison right in suggesting a causal connection 

 between excess of adrenaline and the appearance of oedema, corresponding 

 to the wet form of beri-beri, it seemed that the investigation of this 

 connection might lead to results of more general pathological importance. 

 While the work was in progress McCarrison himself found reason to withdraw 

 the suggestion, which he had put forward at an earlier stage, so that the 

 position to which my own experiments have' led me is in substantial 

 agreement with that which McCarrison now holds. At the same time it 

 seems worth while to put on record the experiments made on this aspect of 

 the question. 



Finally, McCarrison's observations on the occurrence of similar adrenal 

 changes in inanition, the apparent relation between their incidence and the 

 fall of body weight in pigeons fed on polished rice, and his opinion based on 

 the study of histological material, that the enlargement of the cortex is 

 disproportionately large compared with that of the medulla in the adrenals of 

 these birds, suggested that a partial explanation of the enlargement might be 

 found in the storage in the cortex of the gland of lipoids set free by the 

 breaking down of body tissues. This hypothesis has been tested by observa- 

 tions on the cholesterol content of the blood and adrenals of normal and 

 experimental pigeons. The further possibility that enlargement produced by 

 deposition of lipoids in the cortex might be associated with increased residual 

 content of adrenaline has been tested by feeding rabbits and pigeons on diets 

 containing excess of cholesterol. 



Methods. 



The pigeons used in these experiments were Blue Eocks, less than one year 

 in age. In order to produce polyneuritis I have used artificial feeding with 

 polished rice, except in one experiment, which will be referred to later. In 

 the birds which were artificially fed, polished rice to an amount of 15-20 grm. 

 was introduced daily into the crop. Great care was taken to prevent the 

 birds so fed from becoming " crop-bound." When too much rice was found 



