90 STOCK-POISONING PLANTS OF MONTANA. 



loco weed were left uneaten. No evidence was, in fact, obtained to 

 show that any of the plants had been even slightly browsed upon by 

 the sheep. 



During the progress of field work in Montana in 1900, about 650 

 locoed sheep and 150 locoed horses were seen. The locoed horses 

 were nearly all in one herd, and of the 650 locoed sheep 500 were in 

 one band and 150 in another. The owner of the band in which 500 

 locoed sheep were found had lost during the preceding winter 700 

 sheep from loco weed. The extent of losses among stock from eating 

 loco weeds is probably larger than is usually suspected. The appear- 

 ance of locoed animals has become so common that it attracts little 

 attention, and few reports are made by individual stockmen on the 

 number of animals affected b}^ loco disease. Among sheep the num- 

 ber could be ascertained with comparative ease, but with horses an 

 estimate of the number could only be made after a careful round-up. 

 It is safe to assume that the number of the latter is large, since a few 

 are to be seen in almost all parts of the State. 



EXPERIMENTS. 



The specimens used in experiments 1 and 2 were collected May 25, 

 by Arthur Williams, on gravelly plains near Crow Creek, at Toston, 

 Mont., and were received May 27. They were kept moist in a tin 

 box until May 28. The plants were mostly in fruit, but some speci- 

 mens were still in flower, and when used all parts were turgid as they 

 are when fresh. The larger semi-flesh}^ and coriaceous pods were 

 separated in one lot, while the leaves were put in another. The large 

 fruiting specimen and the small showy flowers shown in PI. X illus- 

 trate the stage of growth of the parts used in experiments 1 and 2. 

 Both parts were extracted with water and 50 per cent alcohol in the 

 same way. 



Fiftj^ grams of the leaves and the flowering top {no large pods) 

 were thoroughly rul)bed up in a mortar with about 90 c. c. of water and 

 allowed to soak over night at ordinary temperature. It was then 

 warmed over a water bath at about blood heat for a half hour, after 

 which the water extract was separated from the fiber b}^ means of a 

 filter pump and ])y squeezing tightly in a strong linen bag. The resi- 

 due was set to soak with about 90 c. c. of 60 per cent alcohol, while 

 the filtrate, to prevent contamination bv molds, was placed on ice 

 and kept cold until May 31. Both the alcoholic and water extracts 

 wore finally made up to 100 c. c. in volume. 



Exjhriment 1. — On May 3, at 11.10 a. m., a j^oung Belgian hare 

 weighing 32 ounces received in the stomach by means of a syringe 10 

 c. c. of the water extract. A slight uneasiness was apparent at 12.45, 

 and a noticoal)lc lack of appetite at 1.35, when five other rabbits, dosed 

 with other extract at the same time, were eating well. At 2.50, 15 c. c. 



