On the Toxic Action of the Bite of the Boomslanj. 271 



XXXIV. — On the Toxic Action of the Bite of the Booms^ang 

 or South-African Tree-Snake (Displiolidus typus). By 

 F. W. FiTZ-SiMONS, F.Z.S., &c., Director, Port Elizabeth 

 Museum, Gape Colony. 



This is the snake which recent events liave made famous all 

 over the Cape Colony. Recently one bit an assistant in our 

 Museum with nearly deadly effect ; then another in our 

 collection of living snakes deliberately swallowed another 

 individual of its own species, almost as big as itself. Tliese 

 incidents have caused heated discussions everywhere, as, in 

 the first place, the Boomslang has been regarded as a non- 

 venomous snake, and, secondly, it has hitherto been believed 

 that when snakes swallow each other it is of the nature of an 

 accident — as, for instance, when two snakes seize and attempt 

 to swallow a frog, rat, or some other form of prey, neith.^r 

 caring to let go, the bigger snake naturally engulphs the. 

 smaller. In the case of the Booraslang referred to, the act 

 was deliberate in every sense of the word. 



Some live frogs were introduced into the cage containing 

 five of these tree-snakes, one of which managed, by superior 

 agility, to capture and swallow several of the former, much 

 to the annoyance of one of its fellow^. The latter worked 

 itself into a state of great excitement and attacked its com- 

 panion viciously, seizing it in various parts of its body. 

 Eventually it gripped the other firmly by the neck and 

 gradually worked its head forwards until it reached the other's 

 jaws, whereupon it began to deliberately swallow it with a 

 succession of spasmodic gulps, accompanied by heaving, 

 forward movements. 



After a lapse of twenty minutes it had swallowed one 

 half of the struggling, writhing victim. I then had it 

 removed and photographed, and, during the process, so intent 

 was it upon the work it had in hand that the swallowing 

 process went merrily on, and the photograph shows it in the 

 act of raising its jaw in order to take another mouthful. 

 Bting desirous of preserving these specimens as evidence of 

 the occurrence, I removed a little tobacco-juice with a feather 

 from a dirty pipe and passed the feather bat\veen the jaws of 

 the Boomslang. 



Almost instantly a curious vibratory thrill passed through 

 the snake from head to tail, the muscles relaxed, and the 

 snake lay a lifeless mass within two minutes of the intro- 

 duction of the tobacco-juice, demonstrating the rapid prussic- 

 acid-like action of this poison upon the vital functions. 



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