24 Mr. C. H. Kellaway. The Effect of Certain 



Six pigeons, which were fed on a normal diet with the daUy addition of 

 1/25 grm. of cholesterol dissolved in 1 c.c. of olive oil, and which were kept 

 for the same period and under the same conditions as the second series in 

 Table II, were also investigated. The results are given in Table XI. 



Here again there is an increase in the content of adrenaline, though the 

 control would be more accurate if the normal birds had had olive oil in 

 addition to their normal diet. 



The production of hypercholesterfemia in normal rabbits and pigeons 

 appears to be associated with a small increase m the content of adrenaline in 

 the suprarenals. 



The Significance of Increased Content of Adrenaline in the Suprarenals of 

 Pigeons fed on Polished Rice. 



The adrenaline in the suprarenal glands represents the balance between 

 production and secretion into the blood stream. It is of course possible that 

 the increased katabolism induced by feeding pigeons on deficient diets may 

 provide more of the precursor or precursors from which adrenaline is built 

 up by the gland, but this must remain a mere speculation. On the other 

 hand, the evidence provided both by the present experiments and by the 

 more extensive work of McCarrison suggests strongly that the increase of 

 adrenaline in pigeons on deficiency diet is chiefly due to diminished output. 

 The large increase which occurs in pigeons as a result of restriction of 

 activity by caging, the increase which results from inanition and the associa- 

 tion of such increase with the diminution of muscular and general metabolic 

 activity in pigeons fed on deficient diets, whether polyneuritis were produced 

 thereby or no, all point in the same direction. 



The picture presented by pigeons on a deficient diet is in accord with this 

 view. The progressively falling body temperature, the ruffling of the feathers, 

 which do not lie down closely as would be expected if large quantities of 

 adrenaline were being turned out into the blood stream, and the sluggishness 

 exhibited by such birds, are all consistent with diminished output. The 

 hyperglycaemia observed in pigeons fed on polished rice, which as Funk (1920) 

 has suggested, might be accounted for by increased output of adrenaline, may 

 easily be explained by the diminished use of sugar by the tissues together 

 with the large excess of carbohydrate in the diet. 



Whether the diminished output is itself due in the main to depression of 

 metabolism, or whether the nervous and mechanical factors already discussed 

 are chiefly concerned, is a matter on which no evidence is available. 



In the present experiments the occurrence of increase in the store of 

 adrenaline in normal birds, which in some cases exceeded the amounts found 



