DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 375 



from the other pelvic extremity of the same frog, were placed in normal saline alone (B), 

 galvanic stimulation applied either to the nerve-trunk or to the muscles caused contrac- 

 tion of the muscle for at least 24 hours. 



When, therefore, motor nerves and muscles are together subjected to the contact 

 action of strophanthin, dissolved in 075 per cent, saline, it is clearly indicated that the 

 motor nerves entirely lose their power of inducing contraction of the muscles at a consider- 

 able period of time before the muscles themselves cease to respond to direct stimulation. 

 Thus, in Experiment L., the motor nerves were completely paralysed within 1 hour 53 min. 

 after both nerves and muscles had been immersed in salt solution containing Stropban- 

 thus, while the muscles continued to respond to direct stimulation for several minutes 

 longer ; in Experiment LL, paralysis of the motor nerves occurred at least 1 hour 15 min. 

 before paralysis of the muscles ; in Experiment LIL, paralysis of the motor nerves 

 occurred at least 25 min. before that of the muscles ; and in Experiment LIIL, paralysis 

 of the motor nerves occurred at least 3 hours 7 min. before paralysis of the muscles. 



The inference appears clear that Strophanthus is capable of exerting a paralysing 

 action on motor nerves, by affecting the peripheral endings of these nerves in the 

 muscles. 



The experiments by which this action has been rendered apparent in frogs, by the 

 employment of normal chloride of sodium solution, to delay the otherwise rapidly-induced 

 paralysis of muscles, confirm the experiments in mammals, in which, without this delaying 

 influence, Strophanthus has been observed to produce paralysis of motor nerves, while 

 muscles supplied by them still contracted, though only feebly, under direct stimulation 

 (see Experiments XVIII. and XXXV.). In both circumstances also, and in both warm 

 and cold blooded animals, a peculiarity of the motor nerve paralysis would appear to be 

 the abruptness of its production. 



This action on motor nerves, however, is obviously of secondary importance when 

 contrasted with the action on muscle ; but still it requires to be taken into consideration 

 in explaining the motor weakness so prominently exhibited in both warm and cold 

 blooded animals after the administration of large doses of Strophanthus. 



Fibrillary Twitches. 



A conspicuous phenomenon among the effects of Strophanthus has incidentally been 

 mentioned in the account of the last and of many previous experiments, viz., the 

 occurrence of spontaneous fibrillary twitches in the muscles. Soon after Strophanthus 

 has been administered to an animal by subcutaneous injection, a slight muscular twitch 

 occurs here and there, and altogether irregularly in time and locality, although first and 

 most distinctly near the position of subcutaneous injection. The twitches then become 

 more frequent, and involve a larger number of muscles, and often also larger fasciculi of 

 individual muscles, until they recur unceasingly over the body, and even in independent 

 fasciculi of single muscles, where either minute or larger fasciculi are twitched in irregular 

 succession. When they have attained their greatest development, the condition of non- 



VOL. XXXVI. PART II. (NO. 16). 3 M 



