PRINCIPALLY SOLANACEOUS AND COMPOSITOUS PLANTS 105 



smooth. This species of Eupatorium has been collected in' Ontario, 

 Maine, Vermont, Massachusetts, Connecticut, New York, New Jersey, 

 Pennsylvania, District of Columbia, Virginia, West Virginia, Georgia, 

 Louisiana, Michigan, Illinois, Indiana, Minnesota, Iowa, Nebraska 

 Oklahoma and Kentucky (Fig. 40). 



Disease. It is conceded by the latest evidence that this plant is the 

 cause of a disease known as trembles in cattle, or milk sickness in man. 

 The name "tires and slows," employed by Howard (1871), Logan (1849") 

 and Byford (1855), is used in some sections and there are other names, 

 such as swamp sickness, river fever, puking fever, stiff joints, colica 

 trementia, morbeo lacteo, ergodeleteria, gastritis, gastro-enteritis, muko- 

 soma, syro, caconemia and paralysis intestinalis. 



Symptoms. The first sign of the disease in cattle is a listlessness and 

 disinclination to move with muscular weakness and trembling, especially 

 when the animal is driven. Such animals, too, are generally constipated, 

 are greatly excited and are disposed to fight. The characteristic stage 

 of trembling is marked also by stiff joints. The animal may sink to the % 

 ground showing great weakness and exhaustion, and may remain on the 

 spot where it has fallen. Animals in this stage may recover, but more 

 often die. Violent exercise causes the dormant poison to become active, 

 and this is especially noticeable when cattle, which have been fattened 

 for market, are driven from the infected localities showing marked trem- 

 bling, while those that remain at home remain healthy. The breath of 

 such animals has a foul odor described as " garlicky," "like chloroform 

 liniment" and "mildly like acetone," "singularly fetid," "pungent and 

 corrosive." 



With sheep the onset of the disease is a loss of appetite and a gritting 

 of the teeth. Such animals are sluggish and manifest a marked disinclina- 

 tion to move. They remain standing in a droopy posture (Fig. 41). Res- 

 piration is accelerated, often jerky and somewhat labored. A marked 

 stiffness of the legs and ataxia characterize the movements in walking. 

 This is shown early and becomes aggravated as time passes. If after a 

 day or two the animal is forced to rise and is driven a few yards, muscular 

 spasm, especially in the limbs, is evident. The sheep then refuses to 

 move, stands with hind limbs placed well under the body and all feet 

 spread apart laterally. The back is arched, the neck is stretched and the 

 head lowered (Fig. 42). Quivering then spreads from the limbs over the 

 entire body becoming more intense until it becomes an involitional tremor, 



