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 cobra-poisoning, paraplegia is a most characteristic symptom; whereas it is exceptional in dogs. Why, then, 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,
