THE WHORLED MILKWEED AS A POISON'OUS PLANT. 25 



examined and the fractions into which the extracts were divided were 

 tested for pharmacological activity. 



The investigation has yielded the following preliminary results: 

 Asclejykcs galioides appears to contain several toxic compounds, some 

 of which are glucosidal in nature. The substance which is respon- 

 sible for the symptoms observed in range poisoning may be extracted 

 from the plant with cold alcohol and is insoluble in hot or cold water. 

 The plant yields water-soluble toxins, probably glucosids, which cause 

 narcosis in experimental animals without congestion of the central 

 nervous system. 



In addition, the plant contains less than 0.01 per cent of an alkaloid 

 which does not appear to be toxic and certainly does not influence the 

 range cases. Attempts to discover toxic saponins in the plant were 

 unsuccessful, 



PART III.— GENERAL DISCUSSION AND CONCLUSIONS. 



SYMPTOMS. 



Generally s^Deaking, the first evidence of intoxication is the loss 

 of control of the muscles. The animal staggers when walking and 

 eventually falls and is unable to rise. Sometimes it is found down 

 before any other symptons appear. At this time there is, in most 

 cases, salivation and there may be marked trembling. 



The horse was in profuse perspiration. The loss of muscular con- 

 trol is most marked in the posterior part of the animal. The period 

 during which the animal can remain upon its feet is generally very 

 short. T^Tien down it generally makes strenuous efforts to rise but 

 falls back with a good deal of violence. This feature was very 

 marked in the case of the horse. It may be noted that in the range 

 cases the animals are said to knock their heads on the ground. Soon 

 there commences a series of clonic spasms. It is shown by the au- 

 topsies that the stomachs are greatly distended with gas, which is 

 also true, to some extent, of the intestines. The formation of the gas 

 continues during the period of intoxication, with some relief by 

 belching and the spasms are correlated with the gas formation. 



The bloat caused by the gas was one of the most noticeable features 

 in the poisoned sheep. Vomiting occurred in one case, but was not a 

 usual symptom. In the spasms the pupils are widely dilated. The 

 spasms may become more or less tetanic in character. Ordinarily the 

 animal throws itself repeatedly into a position of opisthotonos, as 

 shown in Plate VII, figures 2 and 3, and this n>ay be followed by a 

 position close to emprosthotonos. Very characteristic is the posi- 

 tion shown in Plate V, figiires 1 and 4, in which the chin is brought 

 down to the breast in a tetanic spasm. This was shown with especial 

 clearness in Horse 126. Generally in this position the feet were drawn 

 up to the body as shown in Plate V, figure 1. The spasms are some- 



