458 Circumstances under which Knee Jerk is altered, [May 18, 



DESCRIPTION" OF FIOURES. 



Fig, 1 is intended to show the stages in the aspbyxial state at which the knee jerks 

 become exaggerated and are abolished. 



a — Curre from carotid artery. 

 b = Respiratory curve. 

 c — Time curve. 



FlG-. 2 shows the stage when the knee jerk returns, after it has been abolished, and 

 that it becomes exaggerated before returning to its normal condition. 



a = Curve from carotid artery. 

 b = Respiratory curve, 

 c - Time curve. 



FlG. 3 indicates the stages in the asphyxial state at which the alterations in the 

 condition of the knee jerk occur in the rabbit. 



a = Curve from carotid artery. 

 b = Respiratory curve. 



FlG. 4 shows the stages in the asphyxial state at which the knee jerk becomes 

 exaggerated and is abolished, and how these phenomena are related, in point 

 of time, to the asphyxial convulsions. 



a — Curve from carotid artery. 

 b = Respiratory curve. 

 c = Time curve. . 



d = Curve obtained from the extensor muscles of the wrist during the 

 asphyxial convulsions. 



FlG. 5 shows that a response can be obtained on excitation of the motor cortex after 

 the knee jerk has been abolished. 



a = Curve obtained from carotid artery. 

 b — Respiratory curve. 



c = Curve obtained from extensor muscles of the wrist on a single 

 excitation of the cortex cerebri. 



FlG. 6 shows that the motor cortex remains excitable after the stage at which the 

 knee jerk is abolished. 



a = Curve from carotid artery. 



b = Curve obtained from the extensor muscles of the wrist on re- 

 peated excitations of the cortex cerebri. 



