14 



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



The Effect of the Addition of " Marmite " to a Diet of Polished Mice. 



In order to ascertain the effect produced on the adrenals by the addition 

 of " marmite " to a diet of polished rice comparisons may be instituted 

 between the results of Series 4 and 5 and 6 and 7 recorded in Tables V and 

 VI ; between those of Series 8 and 9 in Table VII and finally between the 

 figures given for Series 11, 12, and 13 in Tables III, IV, and V. The final 

 comparison gives clear and definite information and will be discussed first. 



In Table V, Series 13, the effect of the daily addition of 2 grm. of " marmite " 

 to the diet of polished rice is shown. This dose is twice the daily amount 

 required to protect the birds from polyneuritis. 



The average weight of the adrenals per kilogramme of original body weight 

 is 94"7 mgrm., and that of the adrenaline present in the suprarenals is 

 0"361 mgrm. as compared with 84'5 mgrm. and 0'338 mgrm. in normal birds 

 (Table II, Series 11) and 158-4 mgrm. and 0-584 mgrm. (Table IV, Series 12) 

 in birds with polyneuritis, observed at the same time and kept under the same 

 conditions. This amount of " marmite " in addition to affording complete 

 protection against the disease, enables the birds to gain in weight, and 

 prevents the occurrence of adrenal hypertrophy and also of any definite 

 increase above the normal in the store of adrenaline. 



In Series 4 with a daily ration of 1 grm. of " marmite " (Table V) and in 

 Series 5 with a daily dose of 0-75 grm. this result is also indicated, though 

 there are no figures for normal birds whicli are strictly comparable with those 

 obtained from these series. 



The effect of yeast extract, in preventing the adrenal changes caused by a 

 diet of polished rice alone is clearly shown ; in the succeeding sections it will 

 appear that it is much less effective in this direction when the basic diet 

 contains protein or fat, free from accessory factors, as well as polished rice. 



The Effect of the Addition of a Fat free from Accessory Factors to the Diet of 



Polished Bice. 



As a fat free from accessory factors olive oil was selected and Series 6 and 7 

 (Table VI) show the effect of a daily ration of 1 c.c. of olive oil together 

 with 1 grm. of " marmite," and 1 c.c. of olive oil without any " marmite." to 

 the diet of polished rice. The pigeons fed on olive oil and rice without 

 " marmite " (Series 7) exhibited symptoms of polyneuritis in between fifteen 

 and thirty days. 



One pigeon of this series, which had a higher-adrenal content than the 

 others, had a trace of fluid in the pericardium at autopsy, and, in addition, 

 the pectoral muscles were moister than normal. 



