62 



Dr. H. M. Kyle. On the Action of the [June 25, 



was not so distinct as the others, the larger blood-vessels were dis- 

 tended with red blood corpuscles. 



Another symptom which is very apt to be overlooked, but which 

 seems undoubtedly to be due to the Spurge, is a distinct loss of sensi- 

 bility displayed by the trout after being immersed for some time in the 

 solution of the extract. They become quiescent and sluggish, and 

 whether lying on their backs or in the normal position permit them- 

 selves to be touched and moved about by the finger. This paralysis 

 does not extend however to the motor system, because they are able to 

 dart about in their accustomed manner if a sufficiently strong stimulus 

 be given. Only two cases were noticed out of twenty in which the 

 body was contorted and there seemed to be motor paralysis of one 

 side. As death approached this sensory paralysis increased and it 

 required still stronger stimuli to rouse the animal, but except in the two 

 cases mentioned the motor system seemed fully capable of performing 

 its functions until within a few minutes of death. If the solution of 

 the Spurge is strong, death ensues so rapidly after immersion that it is 

 somewhat difficult to detect these various stages, but they are easily 

 followed when death does not take place for an hour or more, as in 

 0*1 per cent, solutions and under. This loss of sensibility is evidently 

 similar to what occurs in the frogs, but in the trout it is more 

 conspicuous. 



Neither macroscopic nor microscopic investigation (the latter by 

 sections) revealed any change in the tissues which could account for 

 the fatal action of the Spurge. The alimentary canal (excluding the 

 gills), the liver, spleen, and kidneys presented precisely the same 

 appearances in the normal trout and in those killed by immersion in 

 solutions of the Spurge. When the Spurge-extract was injected into 

 the abdominal cavity, however, a distinct change was noticed in the 

 vascular system of the alimentary canal. The methods employed for 

 fixing and staining the tissues* were the same in all cases, so that the 

 change to be described could not arise in this way. The capillaries 

 lying in the submucosa within the circular muscular layer of the 

 stomach and intestines were found to be dilated and filled with red 

 corpuscles, showing that congestion had occurred. In the normal 

 trout, and in those killed by immersion bodily in the Spurge-extract, 

 these blood-vessels appeared in section as small loose-walled capillaries 

 containing but few corpuscles and often none at all. This change had 

 evidently been produced by the tannic acid component of the Spurge, in 

 the manner already mentioned when describing the action of the 

 Spurge and tannic acid on the vascular system of the frog. The blood- 



* Fixation, by mixture containing gl. acetic acid (7 parts), 40 per cent, formalde- 

 hyde (3 parts), 70 per cent, alcohol (90 parts). This was found to give better 

 results for epithelium than either corrosive sublimate or Fiernrning's solution. 

 Staining, most usually by hsenialum and alcoholic eosin. 



