CONTAGIOUS LUNG FEVER OF CATTLE. 245 



cases will bo foimd quite miiform, altliougli differing considerably in 

 extent. 



In recent and mild cases in wliich only one lung is affected, the sur- 

 face of the lung may be- smooth ; parts of it collapsed, as in health, with 

 the normal pink color preserved. The affected part is swollen, hard, 

 and mottled. On cutting into this, the older 'diseased portions present a 

 very peculiar marbled appearance. The substance of the lobules is solid 

 and of a dark red color, and the tissue between the lobules is of a yel- 

 lowish-red, more or less spotted with red points, but sometimes of al- 

 most pure yellowish-white color. The more recent deposits are dis- 

 tinguished mainly by a lighter red color of the thickened lobules. 



At a more advanced stage of the disease the lung will bo found harder 

 and of darker color, its tissues having lost a portion of the marbled ap- 

 pearance, the blood-vessels obstructed, and showing how nourishment 

 had been cut off" from the lungs, while the older, darker, and more solid 

 portion of the latter have become detached, so that they remain as for- 

 eign bodies imbedded in the cavities of the diseased tissue. The admis- 

 sion of air into these cavities, by dissolution of the lung tissue, produces 

 the cavernous sounds which the ear can detect in the living animal. 



On taking a warm diseased lung, severing the still healthy portions, 

 making incisions into the parts sohdified, and suspending them so that 

 they may drain, a large amount of yellowish serum, of a translucent 

 character, and varying greatly in weight, is obtained. The quantity of 

 this serum, and of the solidified deposit in a diseased lung, is so large 

 that, from a normal weight of four or five pounds, a lung attains ten, 

 twenty, forty, or even fifty iiounds. 



The condition of the air-passages will be found to vary from one of 

 perfect freedom in the healthy portions of the lungs to a state in which 

 the mucous surface is coated with false membrane, or sohd exudations 

 of lymph in the diseased parts. These passages are sometimes found 

 nearly filled, throughout their whole extent, with a deposit similar to 

 that usually found on the surface of the diseased lung. 



The heart's sack is sometimes found to be thickened by deposits 

 around it, and not unfrequently to contain an excess of serum. The 

 heart itself is contracted and pale, containing a little dark blood. 



The organs of digestion at different stages manifest a state of dryness. 

 The third stomach, which is so constantly packed with dry food in fe- 

 brile diseases, is in the same condition in pleuro-pneumonia. In ad- 

 vanced cases there is found a more or less diffuse redness, and even 

 effusion of blood in the large intestines, with fluid, fetid, and sometimes 

 slightly blood-stained excrement, such as is discharged in life. 



Such briefly, and in language free from technicaUties, are the descrip- 

 tion, cause, symptoms, treatment, and post-mortem appearances of 

 pleuro-pneumonia as gathered from previous publications of this De- 

 partment and other recognized authorities. 



