80 ON THE NATURK AND ACTION OF THE 



4. No reflex action from ligatured leg. 



4.2. No reflex action from lel't leg in 60 seconds when it is 

 dipped in the acid. 



4.10. No reflex action from either leg in 250 seconds. 



The medulla was now divided in order to separate the cord 

 from Setschenow's inhibitory centres. 



4.35. No reflex action can be observed. 



As the operation of dividing the cord somewhat lessens the 

 excitability, in the following experiment the division was 

 performed on the previous day, so that its effects should have 

 passed off before the poison was injected. 



The columns headed " left " and " right " indicate the number 

 of seconds which elapsed before the corresponding leg was 

 drawn out of the acid. 



Experiment LIV. 

 May 15th. — About 3 p.m. divided the medulla of the frog. 

 May 16th. — Suspended the frog by a hook in its jaw. 



When touched the frog draws up its legs, 

 and makes wiping movements on its 

 flanks. 



The point of an aneurism needle was 

 drawn across the spine so as to destroy 

 any remnant of medulla. The frog 

 at once passed into a state of opis- 

 thotonos, but in a few minutes this 

 passed off. 



