Art. V. — Observations on the Movements of the Heart 

 of the Copper-head Snake {Hoplocephalus superbus, 

 Gunth.) in and out of the Body. 



By D. Mc Alpine, F.C.S. 



[Eead June 12, 1890.] 



Having already carried out a series of observations on the 

 movements, both of progression and pulsation, in the hearts 

 of a few sjiecimens from each of the five great divisions of 

 the Vertelirata, and which were communicated to the Royal 

 Society of Edinburgh last year, I thought it might also be of 

 interest to members of this Society, to have the i-esults in 

 the same direction :^rom a few more well-known native 

 animals. 



The two specimens of copperdiead snake, which supply 

 the material for the first portion of this paper, were captured 

 at Oakleigh, on 21st April. The larger of the two was 

 killed on the spot, by severing the spinal cord at its junction 

 with the brain, and the other was taken home alive to be 

 chloroformed. Since it is part of this investigation to see 

 the effect of different modes of death, on the after-movements 

 of the heart, I will describe separately and biiefly these two 

 cases. The heart is situated between i and \ of the length 

 of the body from the head end, and consists of two auricles 

 and a ventricle, the single cavity of which is imperfectly 

 divided by a septum. The first snake killed on the spot in 

 the manner indicated was 30J inches long when full}'- 

 extended, and as Professor McCoy in his "Prodromus" gives 

 the average as 5 ft or 6 ft. for this species, this one would be 

 regarded as rather a small specimen. It was a male, like the 

 othei-, and killed at 2.30 p.m. About 5| hours afterwards, 

 it was opened up from the ventral surface, and the heart 

 was found beating steadil}^ at an average rate of 9^ beats 

 per minute, or 93 beats in 10 minutes. The heart Avas still 

 within the pericardium, which was next removed, and the 

 beats again observed. An average of 8 beats per minute 



