EXPLANATION OF PLATES 
Plate 1. 
Eupatorium urticaefolium, or white snakeroot, showing the character of the leaves and 
flowers. 
Plate 2. 
Fig. A—Ewe 161 in a characteristic standing posture assumed when the animal is seized 
with a paroxysm of trembling. 
Fig. B—The same animal a few minutes later when the tremors have become more acute. 
The animal here, as in Fig. A, has spread apart the feet in an effort to remain 
standing. 
Plate 3. 
Fig. C—At this stage of trembling, a few seconds subsequently, the animal is beginning to 
drop down to a resting posture. 
Fig. D—A characteristic resting posture assumed by Ewe 161 after a violent spasm of 
trembling. Note that the eyes are closed, the ears droop, and the chin is rest¬ 
ing upon the ground. 
Plate 4. 
Fig. E—Ewe 12 in another resting posture commonly assumed by affected animals. The 
same evidences of stupor are present, but the head and neck are extended. 
Fig. F—A state of coma has set in and the animal (Ewe 12) is no longer able to rise. 
Plate 5. 
Fig. G—Lamb 244 in a comatose condition, and her mother (Ewe 171) who is entirely 
normal. 
Fig. H—Guinea pig affected with trembles. This animal is unable to control its move¬ 
ments, and general debility is indicated by the drooping ears and partially 
closed eyes. 
Plate 6. 
Fig. I—A pig at the beginning of trembling. 
Fig. J—The tremors have become so violent within a few moments that the animal has 
settled backward upon her haunches and is squealing. 
Plate 7. 
Fig. K—A resting posture assumed by falling forward from the position in Fig. J. 
Fig. L—The same animal, prostrate. This position may be taken following Fig. K, or the 
animal may topple over from a standing posture. 
Plate 8. 
Fig. M—Acute parenchymatous nephritis. From Lamb No. 244. a, tubule in earlier stage 
of cloudy swelling; b, a tubule in advanced stage of cloudy swelling; c, an 
area infiltrated with round cells and polymorphonuclear leucocytes. 
Plate 9. 
Fig. N—Glomerulitis and cloudy swelling of Lamb No. 200. a, glomerule ; b, tubules in 
state of cloudy swelling. 
Plate 10. 
Fig. O—Tube casts from urine of Lamb No. 200 (a). 
