PRINCIPALLY SOLANACEOUS AND COMPOSITOUS PLANTS 109 



encountered in explaining the excretion of the poisonous principle in the 

 milk for milk acquires tastes and flavors from the feed of animals. The 

 medical practitioner well knows that such substances as opium, morphin 

 and atropin may pass into the mother's milk and act on the nursing child. 

 We have seen how the active principle of mayapple is thus secreted in 

 cow's milk. Notably do organic substances pass into the milk, but many 

 inorganic substances, such as, arsenic, iodine, bismuth, etc., are secreted. 



Cause of Disease. Numerous papers have been written discussing 

 the cause of the disease. These theories may be classified, as follows: (a) 

 mineral poison theory, the ingestion of something from the soil or water; 

 (b) the germ, or microbic theory; (c) the poisonous plant theory. All 

 the weight of evidence is in favor of the latter theory. The experiments 

 have narrowed the poisonous plants down to the white snakeroot, and 

 Mosely (1909) attributed the poisonous action to the presence of alumi- 

 num phosphate (AlPCh) in the plant, but experiments with this sub- 

 stance has not substantiated his claims. A synthetic study of the plant 

 has indicated that there are glucosides present in the sap of the white 

 snakeroot, but the particular glucoside responsible for the disease has not 

 been isolated. Further studies on the nature of the active principle are 

 in progress. No efficient remedial treatment has yet been discovered. 



Ragwort (Senecio Jacobcea). The writer's first acquaintance with 

 this plant, or Stinking Willy, as it is called in Nova Scotia, was with the 

 receipt of specimens of the plant for identification from a former student, 

 Dr. A. E. Cunningham of Antigonish, Nova Scotia with the statement, that 

 it was the cause of the socalled Pictou cattle disease. Not much was 

 learned about the disease until the receipt of the Annual Report of the 

 Department of Agriculture of New Zealand for 1903 where a full detailed 

 account covering fifty pages is given. 



Description. The tansy ragwort, or staggerwort, is a perennial plant 

 with short, thick rootstocks. The stems are stout, simple, branched 

 above, smooth, or somewhat wooly. The lower leaves are petioled, the 

 upper sessile. The leaf segments are oblong-cuneate, dentate, or incised. 

 The heads are numerous, short-peduncled in large compact corymbs. 

 The involucre is narrowly campanulate with linear-lanceolate, acute 

 bracts. The number of ray florets varies from twelve to fifteen. They 

 are yellow with truncate, dentate apices. The disk florets are brownish- 

 yellow. The plant is found in waste planes in Nova Scotia, New Bruns- 

 wick and Ontario, and has been found on the ballast about New York 

 and Philadelphia having been introduced from Europe, where it is native. 



