PRESIDENTIAL ADDRESS — SECTION C. 31 



There are three great divisions or classes of snakes, viz., 

 the Aglypha or solid-toothed snakes: These are all non-venomous. 

 Most, but not all of them, kill their prey by constriction. The 

 second division is the Opisthoglypha or Back-fanged snakes, all 

 of which are venomous to a greater or lesser degree. These 

 snakes have the poison apparatus in a transitional condition of 

 development. Some of this group have recently been shewn to 

 be us highly venomous as the dreaded cobra. The third division 

 i- the Proteroglypha. The snakes of this group, without excep- 

 tion, possess the poison apparatus complete, and the fangs are set 

 in the front of the upper jaw. 



The Mole Snake and the House Snake (Pseudaspis cana, 

 and Boodon lineatus) are types of the non-venomous (Aglypha) 

 kinds. 



The Boomslang (Dispholidiis typus) and the Herald or Red- 

 lipped snake (Leptodira hotambecia) are examples of the Opis- 

 thoglypha or Back-fanged group of snakes, and the Puff Adder 

 and Cobra are type:; of the Proteroglypha or front-fanged divi- 

 sion. 



There is no sure way of discovering whether any unknown 

 snake is of the harmless or venomous class except by the careful 

 examination of its teeth. Of course anyone can soon become 

 familiar with the appearance of the different kinds or species of 

 snakes and may identify them at a glance. The harmless division 

 of snakes do an immense amount of good, for the majority of 

 them subsist chieflv upon rats and mice. The agriculturist has 

 a valuable asset in the many harmless or non-venomous snakes 

 of this country. Unfortunately, all snakes are alike to him, and 

 are killed at sight. A House Snake (Boodon) is far more useful 

 in a house than a cat. for it can pursue the rats and mice to their 

 innermost haunts, and even dispose of the young rodents in their 

 nests. 



There are a considerable number of species belonging to the 

 Back-fanged or Opisthoglypha division of snakes in South Africa. 

 Until lately this group has been regarded as only venomous to a 

 •light degree, anil none of the species was considered to be in 

 any way dangerous to human life. 



However, four years ago an assistant at the Port Elizabeth 

 Museum was bitten by a Boomslang, which is one of this despised, 

 back-fanged division. The man hovered for many days between 

 life and death, but eventually recovered. I subsequently con- 

 ducted a long series of experiments with this species of snake, 

 and found that, weight for weight, the venom of the Boomslang 

 was equal in its toxic or poisonous power to that of the Cobra. 

 Other snakes of this back-fanged group were also tested and 

 found to be exceedingly venomous. This is more far-reaching 

 than on first thoughts might be supposed, for the whole trooical 

 and semi-tropical world abounds in snakes belonging to this back- 

 fanged group, which are regarded as venomous only to a 

 slight degree. If several of the South African species have been 

 shewn to be highlv venomous, it is. reasonable to infer that a 



