DISEASES OF SWIXE AND OTHER ANIMALS. 59 



toward the natural standard, tlie bowels became more regular, tlie ap- 

 petite improved, the skin cleared u]), and all the bad symptoms steadily 

 diminished. As it was not our object to preseiTC them they were either 

 sacrificed or ag^ain inoculated, so that the too fi^equently tardy and im- 

 perfect or uncertain convalescence was not verified in our pens. 



POST-MORTEM LESIONS. 



In considering the morbid anatomy of the disease, the lesions of the 

 skin referred to above under the head of symptoms need not be again 

 recorded. 



The diaracteristic lesions were found especially in the digestive or- 

 gans, the IjTuphatic glands, and the lungs, though the serous mem- 

 branes and other tissues were by no means always exemi)t. 



Digestive organs. — In four cases the tongue was the seat of spots of a 

 deep-blue color, ineffaceable by pressiu-e, and in three cases it bore dis- 

 tinct ulcers, similar to those to be described later as existing in the 

 large intestine. Similar ulcers ai)peared on the soft palate, in two 

 cases, and on the tonsils in one. In four cases the pharynx bore indeli- 

 ble blue spots of extravasation, but no distinct ulceration. In one in- 

 stance a white concretion in four minute lobes, like pins' heads, was 

 found on the mucous membrane on the back of one arytenoid cartilage, 

 consisting of rounded nucleated cells and granular matter. In one case 

 only did the gullet show patches of congestion. The stomach always 

 contained a fair amount of food, usually smelt intensely acid, the ex- 

 halation fuming with ammonia, and presented on the mucous membrane 

 of its great curvature a mottled, dark-brown discoloration, as is often 

 seen in pigs that have been starved for some time prior to slaughtering. 

 In four cases this membrane bore patches of thickening from ^ to 1 

 inch in diameter, of a deep-red color, from blood extravasation into and 

 beneath the mucosa. In two cases it bore a dirty yellowish-white pel- 

 licle of diphtheritic-looking false membrane, the microscopic characters 

 of which will be noted hereafter. In one case slight erosion of the mem- 

 brane had ensued, but without the formation of any slough. 



The small intestines constantly presented spots of congestion, and some- 

 times extended tracks of the same, with softening of the mucous mem- 

 brane and excessive production of mucus. The spots were easily over- 

 looked unless when the entire length of the gait was slit open and 

 carefully examined, but when closely examined they presented not only 

 the branching redness resulting from coagula,tion of blood in the capil- 

 lary blood-vessels, but also microscopic extravasations of the blood out 

 of thin natural currents. Another i^oint which served to characterize 

 these limited congestions was a greater or less hsemorrhagic reddening 

 of the mesenteric glands immediately adjacent to the congested spots. 

 In three cases only were distinct erosions found on the small intestines, 

 and in one, ulceration with the dirty-white central slough so common in 

 the large intestines. The edge of the ileo-ctecal valve was t^vice the 

 seat of a sloughing ulcer, and in four subjects the glandular follicles of 

 Peyer's patch were enlarged at this point, a condition which is, liowever, 

 not uncommon in pigs killed in health. 



In the large intestines the lesions were at once more constant and more 

 advanced. The caecum was the seat of dark-red patches from conges- 

 tion and extravasation in six cases, the colon in six, and the rectiun in 

 five. Ulcers appeared on the cfecum in eight cases, on the colon in seven, 

 and on the rectum in three. In two cases the whole length of the large 

 intestine was the seat of great thickening of the mucous membrane, 



