50 Kansas Academy of Science. 



quires not only careful physiological and chemical investigations 

 of a peculiar and delicate kind, but the closest and long-continued 

 observation. We have had hearsay evidence enough on this sub- 

 ject, and now we need to go at it in earnest, in a way that will be 

 recognized by scientific men, and investigations should be pushed 

 to the farthest limits without any short-sighttd regard for the 

 cost." It was further urged that experimental work upon the field 

 was necessary for the final settlement of the question of loco 

 poisoning. 



In the year of 1905 the United States government took up the 

 investigation of loco in a very elaborate manner. A feeding sta- 

 tion was located at Hugo, Colo., under the general direction of Dr. 

 Rodney H. True, of the Bureau of Plant Industry, placing the sta- 

 tion under the immediate supervision of C. Dwight Marsh. At the 

 same time that this field work was in progress, pharmaceutical ex- 

 periments upon animals, using the concentrated extract of the 

 plant upon them, were conducted in the laboratories of the Bureau 

 of Animal Industry by Dr. A. C. Crawford. As the works of these 

 two scientists are now completed, it is well to refer to their classic 

 reports, published by the Bureau of Plant Industry (Bulletins 

 Nos. 112 and 129 of the Bureau of Animal Industry). It would 

 be impossible to give a resume of these two bulletins, but a suflB- 

 cient number of extracts from these publications may suffice. 



Crawford found by his experiments upon rabbits ttat "concen- 

 trated aqueous extracts of the drug induced death." A series of 

 records are made showing that rabbits were killed after administer- 

 ing the extracts in various ways, by subcutaneous injections, etc. 

 In summing up his experiments upon rabbits, he says: "The ex- 

 periments indicate that an acute form of poisoning may be induced 

 by feeding concentrated extracts of Astragalus mollissitnus and 

 Aragallus lamhei'ti, from Hugo, Colo., and Imperial, Neb., to rab- 

 bits, and that if the extract be given in smaller and repeated doses 

 a more prolonged and chronic condition will follow. The rabbits 

 showing the chronic effects of these plants exhibit symptoms which 

 have a marked parallelism with those reported as occurring in 

 larger herbivora (horses and cattle) on the range when locoed; 

 that is, the loss of appetite, the emaciation and loss of weight, the 

 dullness and stupor, with more or less anesthesia, the disturbance 

 in the visual function, and the mental symptoms. The occasional 

 abortion compares with what has been observed in larger animals. 

 The dried Astragalus inollissimus and Aragallus lamherti still 

 retained their poisonous properties. Aqueous extracts of the dried 



