190 Manual of Veterinary Microbiology. 



substances capable of wounding the mucosa, thus 

 opening the way for the bacteridia. It has been 

 shown that the spores of charbon can be absorbed in 

 the absence of all intestinal wounds. However, the 

 non-sporulated bacilli' are killed by the gastric juice 

 so that their action can only take efiect in the passages 

 anterior to the stomach, and hy a solution of contin- 

 uity. Experiment has shown that the addition to 

 contaminated fodder of substances capable of ex- 

 coriating the mucosa (thistles, husks of barley) in- 

 creases the mortality from charbon. At the wounds 

 thus produced there is first developed a tumor, from 

 which invasion proceeds by way of the lymphatics. 



We bave seen that, if the charbon bacilli have them- 

 selves great resistance, this faculty is possessed to a 

 still greater degree by their spores. It is, morever, 

 under this last form that the contagion of charbon 

 persists on certain farms in such a way as to give the 

 disease an endemic character. The contagion having 

 once been deposited on a field, even on a limited part 

 of the same, it remains there for years, contaminating 

 the vegetation which grows upon it. The spores have 

 been found on the surface of the ground above a grave 

 closed for twelve years. The disease occurs during 

 the pasturing season or in winter, according as the 

 herbage is consumed while growing or after harvest- 

 ing, in the form of hay. The most frequent cause of 

 these endemic foci resides in the manner of burial of 

 charbonous carcases : in spite of the layer, of greater 

 or less thickness, by which they are covered, the spores 

 produced in these bodies * find their way to the sur- 



* [It seems to be well established that spores are not formed in 



