1S93.] Correlation of Action of Antagonistic Muscles. 409 



reduce the difference between the time of onset of the rigor in the two 

 hind limbs ; but still, in each case, the hamstring muscles on the 

 side corresponding to the section of the posterior roots entered 

 rigidity later than in the fellow limb. The effect of section of the 

 hamstring branch of the sciatic trunk npon the time of onset of 

 rigor in the extensors of the knee, the cord having been previously 

 divided at the 1st lumbar segment, was then proceeded to. Twelve 

 experiments were made, bnt the results obtained were conflicting. 

 In seven of these experiments rigor commenced in the extensor of 

 the side on which the nerve had not been cut before it did in the 

 extensor of the opposite side. In three rigor commenced indubitably 

 rather earlier on the side of nerve section than on the opposite. In 

 two I could not detect that there was any difference between the 

 two sides in the time of onset of the rigor. A point noted in 

 nine of these experiments (it was not looked for in the remaining 

 three) may be mentioned. When death is induced by haemorrhage, 

 the cord having a short time previously been severed at the top of 

 the lumbar region, various reflexes can be elicited from the hind 

 limbs and tail for some little time after respiratory spasms and all 

 reflexes have vanished from the body in front of the level of the 

 section. There is in the Cat an ear reflex which generally outlasts 

 others under chloroform or ether administration, and often out- 

 lasts them by a considerable time. Indeed, so soon as this reflex has 

 disappeared, the respiratory movements are reduced to a dangerous 

 extent. It consists in a laying back of the pinna of the ear, the 

 pinna being frequently twitched several times : it is elicited by 

 sharply twisting the tip of the pinna. The corneal reflex and still 

 more the knee jerk are both extinguished by chloroform and ether 

 for some time before this ear reflex disappears. This reflex may in 

 the Cat, like Dastre's reflex from the gum of the upper jaw in the Dog, 

 be termed the reflexus ultimus. But when death is induced in the 

 manner above mentioned, the knee jerk outlasts the ear reflex by as 

 long in some experiments as four or five minutes ; and in the limb 

 in which the hamstring nerve has been divided the jerk persists 

 longer than in the fellow limb. 



Finally, I examined the effect of bandaging one knee in full ex- 

 tension, the other in full flexion, after previously severing the cord at 

 the 1st lumbar segment. The bandages after an interval were re- 

 moved. The jerk on each side was then found to be good, and 

 rather brisker in the knee that had been flexed than in that which 

 had been extended. Death was induced by haemorrhage. No 

 difference between the time of disappearance of the jerk on the two 

 sides was detected. In each of five experiments performed the 

 quadriceps extensor and the crural muscles became rigid later on the 

 side that had been flexed than on the other side, but the hamstring 



VOL. Lin. 2 G 



