32 Proceedings of the Royal Society of Victoria. 



exhaustion of energy. In four successive minutes, 10, 12, 

 14, and 13 beats were recoided. Shortly after, tlie heart 

 practically ceased to beat, although up to this the entire 

 heart beat — ventricle and auricles — in regular alternation. 

 Ten minutes after the last record there was no visible 

 movement of the ventricle, although five minutes later the 

 left portion of it showed very faint movement, but soon 

 ceased. Thei-e were still very faint indications of movement 

 at the junction of the auricles and ventricle, but we may 

 say that the heart ceased to beat as a whole nearly three 

 hours after the administration of chloroform, and two and a 

 half hours after excision. The exact times were : — Chloro- 

 form administered 8.15 ; taken out 8.49 ; heart excised 9.5 ; 

 last recorded beat of ventricle (13) at 11.38 and certainly 

 still beating feebly at 11.40; so that the excised heart beat 

 as a whole for 2 hours 35 minutes at least. 



The contrast in the time of pulsation between this and 

 the previous heart, is marked, both of which were taken 

 from chloroformed snakes. The former with its auricles 

 beating for 6 hours at least, and its ventricle for fully 

 3 hours, while the latter only pulsated altogether for about 

 2| hours after excision. An explanation, however, lies in 

 the fact, that a large portion of the heart's store of energy 

 was used up in the progressive movement, for it was usually 

 found in the frog's heart that the duration of pulsation was 

 lessened when progressive movement occurred. The tem- 

 perature M-as pretty constant throughout at 20° C. 



Summing up the principal results obtained, they may be 

 presented as in the following table, which gives only the 

 maximum results in each case : — 



Table I. 



As regards the beats per minute, they vary considerably 

 according to circumstances. The pulse-rate of the snake, 



