252 CONTAGIOUS DISEASES OF DOMLSTICATED ANIMALS. 



aud mediniu of the patho<;fenic principle is the saliva or slaver of the 

 Southern cattle deposited by them, not only wherever they graze and 

 wherever they drink, but also often dropping in strings from their 

 mouths when on their march. Any one familiar with droves of Texaa 

 and Cherokee cattle will have observed that they produce more saliva 

 and slaver more profusely than any other cattle not driven, or at rest j 

 and cattle, when grazing, while grasping with their tongues a bunch of 

 grass, and drawing it into their mouth to be cut off by their incisors, 

 necessarily soil the stubbles which remain standing with their saliva, 

 particularly if slavering, as traveling Texas cattle always do. This 

 saliva or slaver is somewhat sticky, and the microscopic organisms 

 (bacteria) it may contain are thus temporarily glued to the grass that 

 remains on the ground. The bacteria, thus deposited with the slaver 

 (saliva and mucous secretions of the mouth), And a new soil which 

 offers them all the conditions necessary to their existence and prop- 

 agation, particularly if old and decaying grass or vegetation, as is 

 usually the case, is existing among or between the stubbles of the grass 

 that has been torn oft'. Dew and rain afterward provide the neces- 

 sary moisture and also the means of further distribution. If the South- 

 ern cattle, before being shipped or started on their journey toward the 

 Korth, take up on their native range or at any place between their 

 Southern home and their ^Torthern destination, but south of a certain 

 latitude, the pathogenic bacteria of southern cattle fever — and there 

 can be hardly any doubt that bacteria which have their source or origin. 

 in the South constitute the infectious principle or the cause of that dis- 

 ease — either with their food or their water for drinking, the bacteria, of 

 course, will first pass into the paunch, where they find all the condi- 

 tions (a suitable medium, warmth, and moisture) necessary to their ex- 

 istence and propagation. Ascending to the cavity of the mouth with 

 the juices of the paunch when the animal is ruminating, they find a 

 new and, at the same time, excellent medium in the saliva and mucous- 

 secretions, and thus it becomes possible not only that the bacteria re- 

 tain their vitality, and that the "Same vastly increase in numbers, even 

 if the journey of the cattle, as to time and distance, is a long one, but 

 also that one herd of Southern cattle is able to infect a large territory 

 (trails, pasture-grounds, &c.), at a long distance, a thousand miles or 

 more from their native range. I might advance several more argu- 

 ments in proof of the assertion that grazing grounds, trails, pastures, 

 yards, water-holes, &c., are infected by means of the slaver, and that 

 all other theories are untenable, but to do so will be in time, and can 

 be done with much more force, after it has been proved beyond a doubt 

 that a certain kind of bacteria constitutes the true and the sole cause 

 of the disease. To conclude, I may be allowed to remark that all the 

 phenomena of an infection — the non-volatile character of the infectious- 

 principle, the varying period of incubation, the more frequent occur- 

 rence of the disease in difi'erent seasons according to latitude, the kill- 



