1903.] Action of the Poison of the Hydropliidee. 



317 



The above experiment was repeated in a rabbit, with a precisely 

 similar result to that just detailed, the respiratory centre failing first, 

 quickly followed by paralysis of the phrenics, although the diaphragm 

 still responded to direct excitation. The muscles of both limbs (one of 

 which was ligatured before the injection of the poison) contracted well 

 immediately after death to both direct stimulation and that through 

 the sciatic nerves. In this experiment the respirations failed very 

 rapidly, ceasing at the end of two minutes, and no convulsions ensued, 

 in spite of the motor end-plates not being paralysed, so that in this 

 instance the absence of convulsions could not be due to muscular 

 paralysis, but only to complete paralysis of the respiratory centre. 



Action of tlie Spinal Cord Reflexes. 



In the case of Cobra poisoning Brunton and Fayrer showed that 

 the spinal cord is paralysed from below upwards, the hind legs being 

 first affected. C. J. Martin also found that a direct poisonous 

 action on the spinal cord was produced by Pseudechis venom. 



In order to test this point a frog was etherised, and after a ligature 

 had been tied round the right thigh, excluding the sciatic nerve, a dose 

 of 5 milligrammes per kilo, of Enhydrina poison was injected into the 

 dorsal lymph sac, and the reflexes induced by stimulating the skin of 

 different parts of the body with an interrupted induced current with 



