62 DISEASES OF SWINE AND OTHER ANIMALS. 



served around the roots of the brLstles, and it may be added that the 

 bristles always stand erect and harsh. Moreover, in addition to the 

 general unthriftiaess and scuriiuess of the skin, it tends early to become 

 coated with greasy exudation, resultiug usually in the black concretion 

 akeady mentioned and soluble in ether. This is manifestly a product 

 of the hair follicles and their sebaceous glands, and accordingly a section 

 through one of these shows the deep congestion of the capillary plexus. 

 (See Plate IX, Fig. 2.) 



Intestine. — Sections through those portions of the mucous membrane 

 which are merel}^ congested and reddened, but without ulceration, shows 

 stagnation and blocking of the capillary vessels in the mucosa and sub- 

 mucosa, with thickening and softening of the textures, and especially of 

 the epithehal layer. This last contains a great excess of granules and 

 aggregations of granules into cell forms (giant cells of Kleiu), while the 

 epithelial cells themselves are reduced in size and contain enlarged 

 nuclei. As formerly pointed out by Klein, the degeneration is often 

 greatest around the openings of the crypts of Lieberkiihn, and in their 

 interior, while their cavities are not unfrequently filled with extra vasated 

 blood. Besides the above are found lymj)hoid and wandering blood 

 cells, crystals of haematine and closely aggregated masses of granules 

 stainiug deep purj)le blue in hsematoxylon and insoluble in caustic potass 

 — the micrococci of Klein. These last are especially abundant on the 

 surface, but extend into the deeper fibrous layers as well. In severe 

 cases the epithelial layer may be raised from the mucosa by a consider- 

 able dark-red clot, though the escape of blood in large amount is more 

 frequent under the mucous membrane, so as to separate it from the mus- 

 cular coat. 



The ulcers with a central slough present at their base the same char- 

 acters as the congested mucous membrane, as regards cellular and gran- 

 ular prolilbration, blocking of vessels, exudation, and microscopic extra- 

 vasation. The slough may be shown to be made up mainly of small 

 nucleated cells and granules, but it retains under the microscope its close 

 laminated appearance, caused by the gradual extension in depth and 

 breadth by the death of successive layers of the mucous membrane. It 

 contains numerous groups of the granular bacteria already referred to, 

 and extending down to its deepest strata. 



LympJiatic glands. — As regards the lymphatic glands, I need only 

 repeat the statement of Klein, that the blocking of vessels and extrav- 

 asation of blood is most commonly into the outer or cortical portion 

 alone ; in the more severe forms in which the medullary part is also im- 

 plicated, the blood etfusion is often confined to the lymph-channels and 

 the connective tissue-partitions, while the glandular cylinders escape. 

 It is in cases of longer standing that the cell changes are the most 

 marked. Then there may be found in the lymph-channels the giant 

 cells already mentioned, and the groups of granular-looking micrococci, 

 similar to those found in the intestinal ulcers, as well as lymph-cells of 

 an abnormally dark granidar aspect. 



Organs of respiration. — The characteristic lesion of the lungs is lobular 

 pneumonia, the exudation taking place most abundantly into the con- 

 nective tissue between the lobules, and there assuming a dark color by 

 reason of the abundant escape of blood-globules. On making a micro- 

 scopic section across the smaUer air tubes and air sacks, we lind in the 

 comiecti^'c tissues generally, and in the walls of the alveoli and around 

 the bronchia an exudation containing an excess of small round lym- 

 phoid cells and granules, and in the air cells themselves accumulations 



