UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 125 
Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Chief, 
and the Bureau of Animal Industry, A. D. M elvin, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
May 13, 1915 
ZYGADENUS, OR DEATH CAMAS 
By 
C. DWIGHT MARSH and A. B. CLAWSON, Physiologists 
and HADLEIGH MARSH, Veterinary Inspector 
CONTENTS 
Introduction 
Description of Zygadenus 
Common Names of Zygadenus . . . 
Poisonous Species of Zygadenus . . 
Losses of Live Stock by Zygadenus . . 
Animals Poisoned by Zygadenus . . . 
Symptoms Produced by Zygadenus 
Poisoning 
General Statement of Experimental 
Work 
Symptoms in Sheep Observed at the 
Greycliff Station 
Symptoms in Horses and Cattle . . 
Autopsies 
Page 
Toxic and Lethal Dose of Zygadenus 
Venenosus for Sheep 30 
Experiments with Horses and Cattle . 34 
Comparative Toxicity of Different 
Species of Zygadenus 35 
Does Toxicity Vary with Locality . . 35 
Effect of Repeated Feeding in Produc- 
ing Immunity or Increased Suscepti- 
bility 37 
Remedies 37 
Methods of Preventing Losses ... 43 
General Summary 44 
Literature Cited 45 
WASHINGTON 
GOVERNMENT PRINTING OFFIGE 
1915 
