198 THE UNIVERSITY SCIENCE BULLETIN. 



acid from the plant. He experimented on a dog and came to the 

 conclusion that the loco disease is due to the indigestible character 

 of the plant. 



Dr. Mary G. Day ('89) made a chemical analysis of loco weed. 

 She experimented on a cat and rabbits. Her conclusions were that 

 there is a poison in loco weed which will cause illness and death, 

 and may be experimentally given and the same results obtained 

 in cats and rabbits; and that the poison must be weak, or if strong, 

 present in a very small amount. 



Professor Mayo ('93) gave a good account of the symptoms. 

 He said there is no evidence of a narcotic; the effect is due to 

 malnutrition and malassimilation. 



Ruedi ('95) experimented on sheep. In his chemical study he 

 separated "locoin," a base, which he considered harmless, and 

 an acid which is harmful. 



Crawford ( '08) claimed that barium in loco weeds is the poison- 

 ous principle, and tried to support his theory by numerous ex- 

 periments on sheep and rabbits. 



Marsh ('09) told of experiments on feeding and attempts at 

 cure. He said advanced cases are hopeless; they may recover if 

 taken early and put on good feed away from loco weed. He added 

 that injections of sodium cacodylate or strychnine, or the two 

 together for cattle, or Fowler's solution for horses, have been 

 known to help. In 1912 he tried antidotes suggested by Crawford 

 with no success. 



Alsberg and Black ('12) tried to substantiate Crawford's con- 

 tentions for barium, but failed to do so. 



The loco disease in Kansas is nearly all due to Astragalus 

 mollissimus, the purple loco weed. Oxytropis or AragaUus lam- 

 berti, the white loco or rattle weed, is more plentiful farther west. 

 Of these the stock eat the AragaUus more readily, but the Astrag- 

 alus is much the more poisonous. Other species of Astragalus 

 and AragaUus have been found to be poisonous, but these two 

 only are widespread enough to be of great economic importance. 



Astragalus mollissimus of Kansas prairies has a short stem with 

 long pinnately compound leaves, all very hairy, so that they ap- 

 pear silvery. The leaflets vary in number from few to thirty- 

 seven or more. The root goes down quite deep. The flowers are 

 purple, arranged on a spike, blooming the last of May and the 

 first of June. These plants are perennial and remain green all 

 winter. They grow in clumps scattered over the pastures, and 

 are not uniformly distributed. They have many enemies, those 



