80 Proceedings of the Royal Society of Victoria. 



9f inches in length, and was killed with chluvoforiu. 

 Unlike the last, the mouth did not gape after death, but 

 the sensitive tip of the tail trembled occasionally until the 

 chloroform had taken fatal efiect. This specimen was only 

 removed from the influence of the chloroform after 

 34 minutes, and 4 minutes afterwards the heart was exposed. 

 For about a minute no sign of movement was observed, then 

 the beating commenced, and for 4 successive minutes the 

 beats were 37, ^•O, 47, and 46 respectively. The pericardium 

 was next lemoved as delicately as possible, and the beats 

 fell to less than half the above, although only two minutes 

 elapsed between the two I'ecords. The beating, however, 

 was very regular, and for 8 successive minutes gave 21 per 

 minute. The heart was now excised, and the beating at 

 first was rather irregular. Two minutes after the last record 

 the beats were 20 per minute, and for 10 minutes in 

 succession, 36, 40, 15, 17, 25, 28, 30, 31, 32, and 33 respec- 

 tively, or an average of about 29 beats per minute. 



During the first three minutes after excision, a very 

 interesting phenomenon presented itself The heart 

 travelled along the moistened plate in the direction of its 

 base, and thus progression as well as pulsation exhibited 

 itself As I was alwaj-s prepared for sucli a movement, the 

 plate on which the heart was laid out had marks to indicate 

 the slightest progress. The distance travelled happened to 

 be the length of the heart itself, viz. jV inch, and the rate 

 of progression -^-^ inch the first minute, jV inch each the 

 second and third minutes. 



There is something positively grotesque at first sight in 

 an excised portion of the bod}^ such as the heart, beating 

 away and moving along at the same time, but I had become 

 so familiar with this progressive movement in the excised 

 heart of the frog, that it was to me not an unexpected 

 occurrence. 



In the excised beating heart, there is an exhibition of 

 energy which is merely a continuation of the habitual Avork 

 of the organ, but in the excised moving heart, there is a 

 display of power for which we are unprepared. Just as in 

 the detached gill, labial palp, or foot of the mussel, we 

 might expect ciliary motion to continue, but not necessarily 

 the progressive movement which they exhibit. The cause 

 of this progres.sive movement in the latter case is evident, 

 being due to the cilia ; but how the exci.sed heart is propelled, 

 and why in the direction of base or apex, I leave to others 



