226 POISONING. 



TAXACEiE (yew FAMILY). 



Taxus minor. — The common yew, or ground hemlock, is called poison 

 hemlock in some places. The leaves of this shrub are probably poisonous 

 to stock, as are those of the European yew. This species is more acces- 

 sible to stock than the western yew {Taxus hrevifolia), which grows only 

 in deep canons. 



YEW POISONING (tAXUS BACCATA). 



The leaves of yew, when eaten in any considerable quantity, are very 

 poisonous. Two ounces to eight ounces, according to the size of the 

 animal, slow the heart's action, produce weakness, staggering, and 

 apoplectic congestion, which may have a fatal result in less than an 

 hour. The bark is less injurious, and the fruit is scarcely poisonous 

 at all. 



The early symptoms, which are only seen in chronic cases, consist 

 in excitement, followed by somnolence and muscular weakness, with 

 slowing of the respiration and circulation. 



POACE^ (grass family). 



Lolium temulentum. — The seed of the darnel, or poison rye grass, an 

 introduced annual especially abundant on the Pacific Slope, is considered 

 poisonous to both man and animals. 



Stipa robusta. — This is a perennial j)lant which is known in Arizona 

 and New Mexico as sleepy grass. It produces a narcotic effect on horses 

 and cattle that feed upon it, but stock bred in that region rarely touch it. 



Zea mays. — The numerous deaths that are frequently attributed to 

 Indian corn are mostly due, not to any poison inherent in the plant, but 

 rather to parasitic or saprophytic fungus growths, as noted under Asper- 

 gillus and Ustilago. The green fodder is very apt to cause severe and even 

 fatal tympanites if the animal's diet is not properly regulated. Death 

 has also been attributed to the presence of nitre (potassium nitrate) in 

 the growing stalks. It is supposed that in very rich soil this substance 

 will sometimes accumulate in the stalks in considerable quantity during 

 prolonged drought. 



POISONING BY THE MALE TUFTS OF MAIZE. 



The green tufts alone are toxic ; the toxicity disappears after drying. 

 Prolonged administration produces nephritic colic and renal lithiasis. 



POISONING BY SWEET SORGHUM GRASS. 



This form of poisoning is characterised by attacks of trembling, 

 tympanites, and frequent attempts to urinate. The heart beats feebly. 



