38 THE ROYAL SOCIETY OF CANADA 



cedure, but there appears to be no way of avoiding them. Two of 

 these errors are particularly important: (1) post-mortem glycogen- 

 olysis cannot be entirely stopped and it may proceed at different 

 rates in different tissues; (2) it is impossible to be certain that the 

 slices of tissues have been dried to the same degree. It might appear 

 as if these errors would be eliminated by dropping the tissues into 

 alcohol immediately after their excision and then drying them to 

 constant weight before digesting with the potash solution. Although 

 we have employed this method on several occasions we have not 

 thereby obtained results that would seem to justify its adoption, and 

 we hav3 therefore endeavoured to eliminate the errors by repetition 

 of the observations on a sufBcient number of animals. The glycogen 

 was determined by a slightly modified form of Pfliiger's method and 

 all results were obtained in duplicate and none are recorded unless 

 the duplicates checked satisfactorily. 



Results and Conclusions 



The following conclusions appear to be warranted by the results: 



1. The heart contains a decidedly higher percentage of glycogen 

 after starvatio7i than after feeding with carbohydrate-rich food. In 

 order to demonstrate this in rabbits it was necessary to take three 

 animals for each observation so as to obtain a sufficient amount of 

 heart for accurate determination of the glycogen. 



In the hearts of three groups of three fed animals each, there was 

 0.150, 0.090, and 0.083 per cent, of glycogen; average 0.108. In the 

 hearts of three groups of three starved animals each, there was 0.160, 

 0.165 and 0.207 per cent, of glycogen; average 0.177. 



The same results were obtained in dogs, in which case the heart 

 was large enough to permit, in each anirnal, of separate determinations 

 in auricle and ventricle. 



i^ec? 3-4 days: 



Ventricle: 0.497, 0.526*, 0.617; average, 0.547 

 Auricle: 0.50, 0.454*, 0.648; average, 0.534 



Starved 3-4 days: \ 



Ventricle: 1.00, 0.583*, 1.05; average, 0.878 

 Auricle : .828, . 428*, . 542 ; average, . 600 



The ventricle is seen to contain, on an average, more glycogen than 

 the auricle but the result is of little value since a considerable pro- 

 *These animals were in an unusually poor condition of general nutrition. 



