21 



accordinor to Flemino^, it is becoming more common in 

 England. It seems from all we can learn that a cold climate 

 is less favorable to the development and propagation of 

 tuberculosis than a warm or tropical one. Veith states that 

 the disease does not occur in animals living in a wild condi- 

 tion, nor even in those which are in a semi-savage state. 

 Spinola confirms this statement, and adds that the afiection 

 is unknown in the Russian steppes, and is rare in elevated 

 regions. According to Zippelius, tuberculosis is most fre- 

 quently developed in deep and narrow valleys, or in densely 

 popuhited localities. The disease causes the greatest rav- 

 ages in damp and dark dwellings with im[)erfect ventilation 

 and drainage." 



Organs attacked and Jiow they apjiear, 



* " Tubercles may be developed in any part of the 

 body, as the lungs, their serous covering, the membrane 

 supporting the bowels, the coats of the intestines, the throat, 

 the spleen, the liver, the pancreas, the ovaries, the kidneys, 

 the bones, especially the ends of long bones, and, in rare 

 cases, the muscles and connective tissue." 



f " Tuberculosis has been observed to attack nearly every 

 organ in the body, but the lungs and lymphatic glands appear 

 to be particularly subject to it. The tubercles in the lungs 

 at first are small, semi-transparent, grayish, or colorless 

 grains, varying from one-sixteenth to one-half an inch in 

 diameter. These gradually increase in size and become 

 yellowish or opaque. Seveial unite and form larger musses 

 of a pale yellow color, and of a cheesy consistency, which 

 finally soften and liquefy. These masses, often as large as a 

 grape and sometimes even much larger, are more or less glob- 

 ular, and may fill the entire diseased portion of the lung, and 

 exhibit a series of hemispherical elevations over the surface. 



"The lining membrane of the thorax and abdomen, and 

 also the membranes covering the brain and spinal cord, are 

 subject to tubercular growths which appear like the pile on 

 velvet, or wart-like growths over the surface. Not unfre- 



* "The Farmer's Veterinary Adviser," Prof. James Law. 



t Bulletin No. 3, Hatch Experiment Station, Massacbusctts Agricnltiiral Col- 

 lege, January, 1889, C. H. Ferniild. 



