LARKSPUR POISONING OF LIVE STOCK. 11 



dose is large, the pulse rate and pressure rapidly fall again and the 

 heart stops in diastole. 



Halin, in concluding his article in 1882, gives the following resume : 



The delphin, after having caused a local irritation, which is not very in- 

 tense in the first stages, manifests its action on the respiration (slowing of the 

 respiratory movements, death by asphyxiation), on the organs of circulation 

 (slowing of the beatings of the heart, lowering of the blood pressure, stopping 

 of the heart in diastole), on the spinal cord (loss of the excito-motor power 

 of the spinal cord, rapidly progressive general anesthesia, convulsions, and 

 paralysis) ; moreover, the muscles are the seat of intense fibrillar shocks. 

 In its toxic elfects delphin then .very much resembles the alkaloids of aconite, 

 as one would expect from the botanical relationships ; it is distinguished by 

 its energetic action on the nerves supplying the muscles, an action which 

 aconitin does not possess except in a feeble degree. 



Keller and Volker in 1913 report the separation from Z>. ajacis 

 of two alkaloids, ajacin and ajaconin. The formula for ajacin 

 is given as C15H21NO4H2O and of ajaconin as Ci^HggNOo. The 

 properties of these alkaloids are given, but apparently no experi- 

 ments were made to test their effect upon animals. 



In 1913 Loy, Heyl, and Hepner made a report of analytical work 

 on Wyoming larkspurs. They isolated an alkaloid in an impure form 

 and made quantitative determinations in D. nelsonii, D. glaucum^ and 

 D. geyeri. They state that of these three species, apparently D. geyeri 

 is the most poisonous. They find in D. nelsmxii that the seed contains 

 of the crude alkaloid 1.27, the flower 0.Y9, the pod 0.60, the root 0.48, 

 the leaf 0.34. In D. glaucum they find in the root 1.79, in the flower 

 0.77 and in the leaf 0.62. In D. geyeri, they find in the leaf and stem 

 1.15 and in the root 0.93. 



As is noted later, page 77, the apparent greater toxicity of D. 

 geyeri may possibly be explained by the age of the plant. 



A review of the laboratory work on the poisonous principles of the 

 Delphiniums brings us to the general conclusion that we have in 

 these plants a poisonous principle similar in its action to that of 

 aconitin. The poison is a local irritant causing strong convulsions 

 in the animals as well as pain and nausea. Its systemic action is on 

 the nervous system, depressing the respiratory and vasomotor centers, 

 and paralyzing the motor centers in the cord. The immediate cause 

 of death, then, is asphyxiation; the heart action also is weak and 

 stops about as soon as respiration ceases. 



In the summing up of the work of the field experimentation on the 

 Delphiniums, it will be noted that these symptoms agree quite fully 

 with those noted in animals poisoned by feeding upon the plants at 

 the Mount Carbon station. 



LOSSES FROM LARKSPUR POISONING. 



It is very difficult to get anything like exact statistical reports of 

 the loses caused by larkspur poisoning. In many localities . all cases 



