220 THE DISEASES AND DISORDERS OF THE OX. 



pale. The action of the heart is tumultuous, and the pulse is 

 well nigh imperceptible. There is often dropsy of the dependent 

 parts, and sometimes, though rarely, ulceration of the joints 

 and glands. The disease in the second and third stages may be 

 complicated by inflammation of the lungs or of the pleurse, 

 which latter may be due to perforation of the serous membrane 

 of the lung, and thus death may quickly ensue. 



Post-mortem Appearances. — If the body is examined after 

 death, tubercles are seen in various parts. These are found in 

 the external portions of the lungs, and in the connective tissue 

 beneath their lining membranes, and in that which divides the 

 lung-tissue into separate lobules. Large portions of the lungs 

 are replaced by the tubercular matter, and they may weigh as 

 much as 60 pounds. Tubercles are found in the lungs, pleurse, 

 lymphatic glands, and other organs. Many tubercles are often 

 massed together ; but each tubercle itself, the essential element in 



Fig. 24. 



From a preparation of caseous matter obtained from pulmonary deposits in 

 Bovine Tuberculosis. Magnifying power 700. (After Klein.) The tubercle- 

 baciUi are seen crowded within two large cells, and also scattered between them 

 as a result of the disintegration of other cells. 



this disease, is a small, round tumour, which is at first semi- 

 transparent, but may afterwards soften or calcify. It is generally 

 spherical, and of about the size of a grain of millet, or 

 hemp-seed. The larger so-called tubercles, spoken of as being 

 as large as a walnut or larger, are in reality aggregations of the 

 smaller ones. Each tubercular mass can only with difficulty be 

 crushed or separated from the surrounding tissues, from which it 

 is not marked ofi" by any definite wall. A tubercle, though itself 

 non-vascular, is yet placed near a small artery. At first it is, as 

 we have said, semi-transparent ; but it afterwards becomes 

 yellowish and opaque. 



