DR THOMAS R. FRASEE ON STROPHANTHUS HISPIDUS. 363 



Experiment XLI. — In a frog, weighing 350 grains, a ligature was tied round the 

 structures of the right thigh, excepting the trunk of the right sciatic nerve. O'l grain of 

 extract of Strophanthus was injected under the skin at the left flank. In 50 min., 

 the voluntary movements were feeble, and respiration very irregular and infrequent. 

 In 1 hour 5 min., nearly constant fibrillary twitches were occurring in the left (poisoned) 

 thigh. In 1 hour 16 min., slight irritation, anywhere applied, caused a series of 

 movements in the body and four extremities, but these movements were more active in 

 the right (non-poisoned) pelvic extremity than in the left. In 2 hours 35 min., mechani- 

 cal or galvanic stimuli, an}>where applied, failed to cause any reflex movements ; but 

 when a galvanic current was passed through the upper part of the cord, contraction 

 occurred in the right (non-poisoned) as well as in the left (poisoned) pelvic extremity. 

 In 2 hours 50 min., each pelvic extremity still contracted when its nerve was stimu- 

 lated. In 3 hours 20 min., however, the left (poisoned) pelvic extremity no longer 

 contracted when its nerve was stimulated, although active movements still occurred in 

 the right (non-poisoned) pelvic extremity on stimulation of the right sciatic nerve above 

 the position of the ligature, or on stimulation of the spinal cord. The muscles of the 

 left thigh and calf and of the thoracic extremities were exposed, and it was found that 

 tbey no longer contracted when directly stimulated, and that cut sections of these 

 muscles had an acid reaction. In 4 hours, the right sciatic nerve and the muscles of the 

 right (non-poisoned) pelvic extremity were still active and responded to stimulation ; but 

 rigor was present in all other parts of the body, being strongest in the thorax and its 

 extremities. 



It therefore appears that the reflex function of the spinal cord is destroyed before the 

 motor columns of the cord fail to conduct impressions, and also before the motor nerves 

 and the skeletal muscles have lost their activity. If Strophanthus acts directly upon the 

 cord, the action is thus limited to the reflex cells or the sensory or afferent fibres con- 

 nected with them. An action on the latter, sufficient to explain the loss of reflex 

 function, is rendered improbable by the circumstance that, in a tied limb, stimulation of 

 a sensory (non-poisoned) nerve-trunk or of its peripheral extremities does not fail to 

 cause reflex movements until stimulation of the poisoned sensory nerves also fails to do 

 so, the motor nerves and the muscles in the poisoned as well as in the non-poisoned 

 regions being still active. 



It is, however, premature to conclude from these data alone that Strophanthus 

 paralyses the reflex apparatus of the cord by a direct and primary action. It has been 

 stated in many of the preceding experiments that the heart early ceases to contract, and 

 it is necessary to determine if this standstill of the heart is sufficient to account for the 

 paralysis of the spinal reflex function. The time-relation between the two events is 

 indicated in the following experiments. 



Experiment XLII. — A ligature was tied round the upper part of the right thigh, 

 excluding the sciatic nerve, of a frog weighing 320 grains. The heart was exposed, and 

 it was found that its contractions were regular, and at the rate of 14 per 30 sec. 



