INFLAMMATION OF THE LUNGS. 631 



earlier or second stage and the grey spots the third or later 

 stage of the disease, which is called — 



A.th. Grey Hepatization, termed by Andral ramollissement gris, 

 or grey softening. In the horse, perhaps the term grey softening 

 may not be inappropriate, but in the ox solidification expresses 

 the condition much more accurately. The cut surface of the 

 part which has run on to this stage presents a grey tint, 

 the redness of the preceding stage having passed away, and 

 the granular character is less distinct. In the horse, dog, &c. 

 the tissue has very often lost its firmness, and has become soft 

 and pulpy, and an abundant dirty-looking puriform material 

 oozes from the cut surfaces. In the ox the grey portions are 

 generally smooth, glistening, and firm. In some instances the 

 smooth, glistening appearance is observed in the inflamed lungs 

 of horses, but the firmness is rarely so great as in the lungs of 

 oxen, in which the tissues of consolidated parts retain their 

 marbled appearance, and acquire a resisting character, or are 

 transformed into a more or less firm cheesy material. In some 

 instances, however, the grey exudate, even in the ox, is broken 

 down into a more or less pulpy material. 



If a portion of hepatized lung be torn, and the torn surface 

 examined with a magnifying glass, the tissue will appear to be 

 composed of a crowd of small red granulations, lying close to 

 each other, air vesicles clogged up, thickened, and made red by 

 the inflammation. In the catarrhal form of pneumonia com- 

 monly seen in the horse, the exudative products are mostly 

 accumulated in the interior of the air vesicles, but in the 

 exudative form (croupous) seen in the ox, and in cases of pleuro- 

 pneumonia in the horse, the exuded materials not only fill 

 the air vesicles but the interstices of the pulmonary connective 

 tissue. 



Suppuration of the lung is a more advanced state of grey 

 hepatization ; the lung is softer, yellower, and more pulpy, but the 

 condition is not materially distinct from the others, as pus cells 

 are present in the advanced stages of pneumonia, and the distinc- 

 tion between softening, grey hepatization, and suppuration is more 

 one of terms than of reality. Diffuse suppuration of the lungs is 

 not rarely witnessed in newly calved cows ; exposed to wet and 

 cold, it runs a rapid course, terminating fatally in three or four 

 days, the lungs being engorged with puriform materials. It is a 



