366 THE SNAKES OF SOUTH AFRICA. 



line the intestine walls. In due time it will find its way into 

 the blood and cause poisonous symptoms, the same as if it 

 had been absorbed in the ordinary way in cases of snake bite. 

 This can be demonstrated by introducing snake venom direct 

 into the small intestines of animals, when in an empty condition. 

 Cobra venom in this way is absorbed and acts more rapidly than 

 Adder venom. 



Adder venoms are destroyed by the digestive juices. The 

 neurotoxins of Cobra venoms are not affected until they come in 

 contact with the pancreatic juice. 



Fig. 145.^ — Harmless little Geko Lizard of South Africa, popularly supposed to be highly 

 venomous, and in consequence is killed whenever seen. It eats insects which are a 

 Pest to man, and ought therefore to be protected. (Life size.) 



Action of Colubrine Venom. 



Colubrine (Cobra family) venom acts directly and speedily 

 upon the nervous system. Viperine venom is slower, and 

 operates both upon the nervous system and blood. If a fatal 

 dose of Cobra venom be injected direct into a vein, it is speedily 

 carried to the heart, instantly stopping the action of that organ, 

 and causing death in a few moments. A dose injected into a 

 vein in the thigh of a dog caused instant death. This effect, 

 however, is only produced when the venom is injected direct into 

 the veins. When Cobra venom is injected into the tissues, as 

 invariably happens in ordinary cases of snake bite, the poison is 

 absorbed less rapidly, and instead of stopping the heart's action, 

 it has a contrary effect, stimulating it into increased activity. 



