30 INDIAN SNAKE POISONS, 



culty of walking with the hind-quarters, due to the local 

 effect of the poison. But even with this source of 

 fallacy it holds good that in men suffering from cohra- 

 poisoning, paraplegia is a most characteristic symptom ; 

 whereas it is exceptional in dogs. Why, th^n, as a rule^ 

 should paraplegia occur in men, and not in dogs ? 

 Standing and walking are to a very great extent reflex 

 acts. A man when walking places one foot on the 

 ground, and the sensation of contact with the ground, 

 serves as a stimulus to a centre in the cord by which the 

 motor impulse to move the other leg is excited, and 

 paralysis of these few lower centres would at once 

 impair the action. But in dogs the mechanism is very 

 different. They move the fore leg of one side with the 

 hind-leg of the other. It is necessary, then, that the 

 centres governing the movements in these limbs should 

 be coupled, so to speak, together. The stimulus that 

 moves the fore-leg of the one side, has to excite 

 simultaneous movement in the hind-leg of the other. 

 Therefore, all the inferior, or rather posterior, extremity 

 of the cord has to do in the case of the dog, is merely to 

 transmit the motor impulse from the fore-part; whereas, 

 in man, the inferior part of the cord has to translate a 

 sensation into a stimulus to excite movement. It is, 

 therefore, probable that the earliest injury inflicted by 

 cobra-poison on the nervous system is a paralysis of^the 

 centres in the lower part of the cord. 



It will have been observed that paralysis of the lips, 



