138 THE SNAKES OF SOUTH AFRICA. 



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. Being desirous of preserving these 

 specimens as evidence of the occurrence, I remo^'ed a little 

 tobacco- juice Avith a feather from a dirty pipe and passed the 

 feather between 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 introduction of the 

 tobacco-juice, demonstrating the rapid prussic-acid-like action 

 of this poison upon the vital functions. 



This Boomslang was a striped, black and 3'ellowish-green 

 male, measuring four feet nine inches, whilst the victim was a 

 female three feet eleven inches long. 



What Naturalists Say. 



The Boomslang is placed in the British IMuseum Catalogue 

 of Snakes by G. A. Boulenger in the family Colubrince, series 

 OpistJioglypha, sub-family Dipsadoniorphince. The definition of 

 the Opisthoglypha is " a division of snakes Avith one or more of 

 the posterior maxillary teeth grooved." Most, if not all, are 

 regarded as poisonous to a slight degree, sufficiently so only for 

 paralysing their prey before deglutition. 



Now, this is a very important point to bear in mind, viz., one 

 of the Opisthoglypha has been classified in many text-books of 

 science as practicall}^ a non-\"enomous snake, or one not at all 

 dangerous to man. 



Sir Andrew Smith, in his " Zoology of South Africa," remarks : 

 " As this snake, in our opinion, is not provided with a poisonous 

 fluid to instil into wounds wliich these fangs may inflict, they 

 must consequently be intended for a purpose different to those 

 which exist in poisonous reptiles. Their use seems to offer 

 obstacles to the retrogression (retention) of living animals, such 

 as birds, etc., while they are only partly within the mouth ; and 

 from the circumstances of these fangs being directed backward 

 and not admitting of being raised so as to form an angle with the 

 edge of the jaw, they are well fitted to act as powerful holders 

 when once the}'' penetrate the skin and soft parts of the prey 

 which their possessors may be in the act of swallowing. 



