216 THE DISEASES AND DISORDEES OF THE OX. 



tubercular matter or with tubercular matter obtained from fowls. 

 There are other points of difference between bovine and human 

 tuberculosis to which we shall refer. 



In cases of tuberculosis there are tubercles in various stages 

 of growth which, so far as can be seen, contain no bacilli. Quite 

 near these, other tubercles may be present in which numbers of 

 bacilli may be found. Now, it has been proved by Dr. Klein 

 and Mr. Lingard, working in co-operation, that tubercular 

 matter in which neither bacilli nor spores of bacilli can be 

 detected does produce tuberculosis when it is injected into 

 healthy guinea-pigs. The well-known deposits were found in 

 the lungs, liver, spleen, and lymphatic glands; and some of 

 them were caseous and contained tubercle-bacilli. As these 

 observers remark, it is probable that spores or bacilli were 

 present, although they could not be detected. This shows that 

 there need not be many bacilli introduced, in order to cause 

 the disease, and it possibly indicates that spores of the bacilli 

 exist, and that they are sufficient to produce the disease. At 

 present, however, it seems that there is no known method 

 of staining spores of tubercle-bacilli, if such spores exist, as 

 in all probability they do. 



There can be no doubt that tuberculosis is capable of being 

 propagated from the parent to the offspring. The taint of this 

 dread malady can sometimes be observed in several members of 

 particular breeds. Cows, and especially milch-cows, seem to be 

 most frequently affected ; and there is no doubt that dark, filthy, 

 /and badly ventilated, ill-drained, dwellings aid the progress of 

 the disease. It is said that the chief indirect causes are pro- 

 longed and excessive milking on the one hand, and on the other 

 a cold and damp atmosphere. Oxen brought from a milder 

 ■country, or from mountainous regions, when transferred to cold 

 and damp districts, and likewise cattle which are used solely for 

 dairy purposes, and especially those which are kept for this 

 object in large towns, and give an abundance of milk, are most 

 liable to the disease. 



Course of the Disease. — Tuberculosis, as is well known, is 

 generally a disease which is not rapidly fatal, but one which 

 lasts often for a considerable time. This statement, so far as is 

 known, applies to all the different kinds of animals liable to be 

 affected with this malady. Unless complications arise, tuber- 



