376 DR THOMAS R. FRASER ON STROPHANTHUS HISPIDUS. 



rhythmical unceasing contractions may be likened to the muscular contractions of the 

 graver forms of chorea ; this Strophanthus-chorea, however, involving in succession 

 independent fasciculi of many single muscles, in contrast with the involvement of entire 

 muscles that occurs in true chorea. After attaining their greatest development, the 

 twitches gradually become less frequent, until the initial condition of single feeble twitches, 

 occurring at considerable intervals, is reproduced, and they then finally cease, the cessa- 

 tion coinciding usually with the time when the motor nerves become unable to excite 

 contractions in the muscles. 



These twitches appear to involve all the striped muscles of the body, and they have 

 been observed even in the muscle of the heart (Experiment XXXIII. ). They are 

 apparently produced whatever be the manner in which Strophanthus is brought into 

 contact with the parts affected ; for they have been observed when the administration 

 was by the stomach, rectum, subcutaneous tissues, or blood-vessels, and also when muscles 

 were immersed in solutions of Strophanthus. In tracings 4 to 7, Plate VIIL, 4 to 10, 

 Plate IX., and 2 to 4, Plate XL, illustrations are given of the curves produced by 

 muscles immersed in Strophanthus dissolved in normal saline ; and the curves graphically 

 display the rapid recurrence of the twitches, as well as their irregularity in time and 

 extent of movement. 



Some experiments were made for the purpose of determining whether they are of 

 nerve or of muscle origin. 



In the first experiment it is shown that the fibrillary twitches are not produced by an 

 action on the brain or spinal cord. 



Experiment LIV. — The brain and the whole of the spinal cord were thoroughly 

 destroyed in a frog, weighing 295 grains. Soon afterwards, - 05 grain of extract of 

 Strophanthus, dissolved in 3 minims of water, was injected under the skin of each thigh 

 (O'l grain in all). In 47 min., feeble and very infrequent twitches were seen at each 

 thigh. They occurred only there until about 57 min. after the injection, when twitches 

 appeared also at the flanks. They increased in frequency, and continued in the thighs 

 and flanks for at least 15 min. They then became less frequent, and ceased to occur at 

 the flanks ; but they continued at the thighs for at least 1 hour 7 min. after their 

 first appearance, or until 1 hour 54 min. after the administration of Strophanthus. 



In Experiments LI., LIL, and LIIL, it has been demonstrated that the fibrillary 

 twitches precede the production of paralysis of motor nerves, and terminate with this 

 paralysis, or soon after it has been produced, and also that they terminate before the 

 muscles themselves have lost the power to contract when directly stimulated. These 

 facts suggest that the twitches might be caused by an action upon the terminations of 

 the motor nerves in the muscles. If they are so caused, they should be prevented from 

 occurring by paralysing the terminations of the motor nerves before the administration of 

 Strophanthus. To obtain this condition, two experiments were made in which the motor 

 nerves were paralysed with curare before these nerves and the muscles in which they 

 terminate were subjected to the action of Strophanthus. 



