POISON OF SOME INDIAN VENOMOUS SNAKES. 29 



3.12. The animal did not seem to be much affected by the 

 poison. Some more injected into left thigh. 



4. Both hind legs became paralysed, and the animal lay with 

 them spread out behind it. The hind part of the body also sank 

 down, so that the abdomen became flattened on the floor, just 

 as with the Dahoia-'poison. 



4.23. Convulsive twitches occur. The animal lies on its 

 side. It is more convulsed than the one killed with Dahoia- 

 poison. 



Action of Cohra-j)oison on Frogs. 



When cobra-poison is injected under the skin of frogs they 

 occasionally become very restless immediately after the 

 injection. This, however, is by no means always the case ; 

 and as similar agitation occurs, often to a much greater extent, 

 after the injection of other substances, it is to be attributed 

 rather to the insertion of the needle than to the action of the 

 venom. A gradually increasing torpor then comes over the 

 animal, sometimes beginning some time after the injection, and 

 then proceeding uninterruptedly, at other times being inter- 

 rupted by occasional movements. The limbs are drawn close 

 up to the body, and the head gradually sinks down between 

 the hands in most instances ; but sometimes, as in Experi- 

 ^ment VITI, the head is held at first much more erect than 

 usual. The power of motion is lost before that of sensation ; 

 for the movements caused by painful stimuli become weaker 

 and weaker, althoiigli they may still follow each application of 

 the irritant. The progressive weakness is well shown in the 

 movements of the hind legs. After the frog has sunk down 

 and is lying flat upon the table, pinching the toes causes it to 

 kick vigorously ; but by-and-by, instead of kicking, it merely 

 draws away the foot from the irritant with a slow wriggling 

 motion. If it is then lifted up from the table, so as to remove 

 the resistance occasioned by friction, the wriggling entirely 

 disappears, and the foot is promptly and easily drawn up to the 

 body when pinched. This weakness seems to depend on the 

 nervous system rather than on the muscles ; for, even in this 

 state of apparent paralysis, the animal occasionally displays 

 considerable muscular power, and is able to spring to a 



