66 BULLETIN" 365^ U. S. DEPAKTMENT OF AGRICULTURE. 



did not appear to be a lack of coordination, and the movements of 

 the animals, while perhaps they might be described as convulsive, 

 could hardly be considered as the movements of violent spasms or 

 convulsions. When the animals attempted to rise, the difficulty, ap- 

 parently, was weakness rather than a lack of coordination of the 

 muscles, and the kicking of the animals appeared to be due to volun- 

 tary attempts to rise rather than to involuntary and spasmodic con- • 

 tractions of the muscles of the legs. It did not seem to the observers 

 that the animals could be said to have convulsions or spasms. 



Bloating occurred in some of the cases, but was not a common 

 symptom. In the cases where it was noticed, it seemed to come 

 as one of the later results of the poison. The bloating doubtless adds 

 much discomfort to the animal, and if it lies with the head lower 

 than the rest of the body, may cause death. It is a matter of com- 

 mon knowledge that when animals die of larkspur poisoning upon 

 the range they bloat very quickly, and it seems probable that death 

 may in some cases be immediately caused by the mechanical effects 

 of the bloating. 



Recovery from larkspur poisoning is ordinarily very rapid. The 

 animal, after becoming well enough to rise, soon walks away, in a 

 short time- begins to eat, and after two or three clays shows no effects 

 of the poisoning. Some stockmen believe that cattle do not thrive 

 after being poisoned by larkspur, but from the experimental work 

 it appeared that no permanent injury was caused. Several of the 

 animals were fed upon the larkspur repeatedly in the same season 

 with no bad results in their condition, except the loss of flesh during 

 the days when the experiments were being carried on. In these 

 experiments of using animals repeatedly they were poisoned as 

 readily the second and third times as the first, or, in other words, 

 there is no evidence from the experimental work of acquired toler- 

 ation ; on the other hand, they were no more susceptible to the effects 

 of the poison because of the repeated feedings. 



THE TOXIC DOSE OF LARKSPUR. 



It was important for practical purposes to determine how much 

 larkspur was necessary to produce poisonous effects. The work of 

 the first season alone did not give very definite indications of the 

 quantity of larkspur necessary to produce poisoning, but taken in 

 conjunction with the work of the succeeding seasons, seems to give 

 results that are quite exact. 



From the accompanying charts (see figs. 6 to 12) one can see the 

 toxic dose of larkspur, this being reduced to a uniform scale for 

 animals weighing 1,000 pounds. They show the quantities of lark- 

 spur necessary to produce the poisoning, the dates of the experi- 

 ments, and the length of time during which the plant was fed. The 



