PRINCIPALLY SOLANACEOUS AND COMPOSITOUS PLANTS III 



in the dairy cow symptoms may be exhibited for even ten days, or a 

 fortnight, in these cows death occurs in from two to five days, the animal 

 being in a visible state of excitement almost bordering on frenzy. The 

 proof that the milk is changed is the refusal of the calf to come to its 

 mother paying no attention to her bellowing. 



Post-Mortem Study. The most striking appearance on skinning an 

 animal in the post-mortem examination is the yellow, bile-stained condi- 

 tion of the tissues. The peritoneum, the fat, and the general viscera all 

 exhibit the same appearance, which may vary from a faint tinge to the 

 proverbial " yellow as a guinea." In cattle, there is frequently a large 

 accumulation of a semi-gelatinous, yellowish exudate, situated subcutane- 

 ously along the inferior borders of the thorax and abdomen. The most 

 marked change is in the liver, which is almost constantly in a state of 

 chronic cirrhosis. The organ is usually smaller than normal, of a dull, 

 mottled, slaty-blue color frequently pitted and almost " hob-nailed, " there 

 being occasionally small dark-blue pitted areas underneath the capsule 

 and throughout the structure. The lymphatic glands are usually much 

 enlarged. 



Feeding experiments and the fact that the Auckland District in New 

 Zealand, where Senecio Jacobaea occurs, is separated by thousands of 

 miles from the Pictou district of Nova Scotia, where the plant is also 

 found, is sufficient proof that the ragwort is the causative agent of the 

 same disease in cattle in both widely separated countries. 



Hay-Fever Plants (Pollinosis). Hay-fever, or autumnal catarrh, is an 

 affection of the upper air passages occurring periodically, usually at or 

 near a fixed date in the early autumn, sometimes in the spring, or summer, 

 characterized by its sudden onset and as sudden termination, and by a 

 swelling of the mucous membranes of the nasal and adjacent cavities, 

 irritating discharges therefrom, and various symptoms of coryza, and 

 occasionally by asthmatic paroxysms. It has been conclusively proved 

 by many authorities that hay-fever does not occur unless we have a 

 conjunction of three necessary factors: 



1. An external air-borne irritant; 



2. A sensitive, or diseased, nasal mucous membrane; 



3. An unstable nerve center. 



The second and third elements are usually associated with a functional, 

 or hereditary predisposition to the disease. The first is associated with 

 the external causative factor. 



