proceedings: biological society 427 



THE BIOLOGICAL SOCIETY OF WASHINGTON 



The 512th meeting of the Biological Society of Washington was held 

 on April 19, 1913 at the Cosmos Club, with Vice-President Hay in the 

 chair and about 30 persons present. 



Henry Talbott exhibited an unusually large tooth of the fossil shark, 

 Carcharodon megelodon. from South Carolina and by way of compar- 

 ison the much smaller teeth of Odontaspes from Chesapeake Beach, 

 Maryland. 



Wells W. Cooke commented on the spring migration of birds, not- 

 ing that this year the yellowthroat, redstart, wood thrush and catbird 

 had arrived three da}' s ahead of schedule time. 



The regular program consisted of a communication by C. D. Marsh, 

 on Stock Poisoning by Larkspur. He stated that ranchmen of the west 

 had long claimed losses of stock due to larkspur, and on scientific in- 

 quiry had found their observations correct, and that the monetary loss 

 was considerable. Altho larkspur occurs in other parts of the world it 

 apparently only causes trouble in the Western United States. The 

 average mortality in affected areas of the west is from 3 to 5 per cent, 

 but as many as 20 head out of a herd of 200 have been fatally poisoned 

 in twenty-four hours. The low larkspur appears to be always dangerous, 

 but the tall only becomes so in August after the fruit matures. The 

 poison is a cumulative one and requires from 3 to 10 per cent of the ani- 

 mal's body weight of larkspur plant to cause death or alarming symp- 

 toms. The symptoms consist of general discomfort, nausea, constipa- 

 tion, a characteristic arching of the back and sudden collapse, followed 

 by partial recovery and a repetition of similar attacks, and if the case 

 is a fatal one, to end in respiratory paralysis and death by asphyxia. 

 Animals do not become immune to the poison. Horses may be experi- 

 mentally poisoned but when feeding on the range do not eat into a patch 

 of larkspur enough to consume a toxic quantity. Sheep are naturally 

 immune to the poison and may be fed a continuous diet of little else 

 than larkspur without showing any symptoms. The cowboy's treatment 

 of the disease is bleeding but the proportion of recoveries by this method 

 is not greater than in natural recovery. Rational treatment consists in 

 placing the poisoned animal on sloping ground with head upward so 

 that the abdominal viscera fall back from the thoracic organs. ^ Drug 

 treatment consists of eserin pilocarpine and strychnine administered 

 hypodermically. Under this method 96 per cent of poisoned animals 

 recover. Alcohol is also effective but less practical. The paper was 

 illustrated by lantern slides, showing the larkspur in detail and on 

 ranges, and numerous animals in various stages of poisoning. The paper 

 was discussed by Messrs. Bailey, Weed, Hitchcock, Gill, Lyon and 

 others. 



The 513th regular meeting of the Biological Society of Washington 

 was held on INIay 3, 1913 at the Cosmos Club, with President Nelson 

 in the chair and 56 persons present. 



