2 EXPERIMENT STATION RECORD. 



'The investigations which were made during the season of 1900 indi- 

 cated clearl}^ that a considerable proportion of the loss by poisonous 

 plants might easily be avoided by a more general diffusion of the 

 knowledge which already exists concerning such plants. In general, 

 however, stock could not at present ))e managed on any lixed basis 

 with reference to poisonous plants, on account of the great difference 

 of opinion which prevails not only among stockmen, but among vet- 

 erinarians and l)otanists, as to the poisonous nature of particular 

 species and as to the time of year when they are most dangerous. 

 Further investigations along this line will probably show that many 

 of the plants which at present are suspected of l)eing poisonous are 

 quite harmless, and that a few species of plants are responsible for 

 nearly all of the serious stock poisoning. 



In order to determine the poisonous or nonpoisonous character of 

 a given plant, it is not sufficient to obtain positive or negative 

 results from a few experiments on rabbits or guinea pigs. As is well 

 known, rabbits are easily excited, and many peculiarities of their 

 actions after being fed with extracts from plants are due to the fright 

 or nervous excitement of the operation. Carefully controlled feeding 

 experiments, either with extracts from poisonous plants or with the 

 plants themselves, on sheep or cattle, and conducted under conditions 

 as similar as possible to natural field conditions, should yield results 

 which will be much more convincing to the practical stockman and to 

 other investigators of this subject. In a sheep-raising region the 

 animals necessary for such experiments are readily furnished by sheep- 

 men, and feeding experiments, as well as experiments with remedies, 

 could be conducted upon sheep at the same time that cases of poisoning 

 occur under natural conditions, and therefore with plants in the stage 

 of growth in which they are eaten by sheep or cattle on the ranges. 

 Many feeding experiments with poisonous plants are open to the criti- 

 cism that they were made with suspected plants in a different stage of 

 growth from those which were eaten by the poisoned animals.^ 



In future experiments with poisonous plants it would be well to 

 bear in mind that the active principles of such plants may vary 

 exceedingly in different stages of growth of the plant, and even during 

 different hours of the day. The possibility of a plant being poisonous 

 at one time and not at another must constantly be reckoned with if 

 experiments with these plants are to yield conclusions which will be 

 established beyond criticism. 



Experiments during the season of 1900 showed pretty conclusivelj" 

 that potassium permanganate, if administered soon after the symp- 

 toms of poisoning develop, may be depended upon, as a rule, to oxidize 

 and destroy the plant alkaloids contained in the stomach and to pre- 

 vent the progress of the symptoms of poisoning. This substance was 

 administered b}^ direct injection through the l)ody wall or ])y drench. 

 Further experiments on a larger scale with potassium permanganate 



