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 removed a little 
tobacco-juice with 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 of the striped, black and yellowish-green 
variety, measuring four feet nine inches, whilst the victim was the 
brown variety three feet eleven inches long. 
WHAT NATURALISTS SAY. 
The Boomslang is placed in the British Museum Catalogue 
of Snakes by G. A. Boulenger in the family Colubrine, series 
Opisthoglypha, sub-family Dipsadomorphine. The definition of 
the Opisthoglypha is ‘‘ a division of snakes with 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 
paralyzing 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 practically a non-venomous snake, or one not at all 
dangerous to man. It is my present intention to prove the 
opposite. 
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 which 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 they penetrate the skin and soft parts of the prey 
