ANATOMICAL CHARACTERS. 487 



Anatomical Characters. — The after-death appearances appre- 

 ciable by the naked eye in the hmg-tissue of horses which 

 have fallen victims to a serious invasion of pulmonary con- 

 gestion are perfectly characteristic. 



There is distension and general engorgement of the pul- 

 monary vascular system with dark-coloured fluid blood, with 

 occasionally irregularly distributed circumscribed hiemorrhagic 

 effusions from rupture of minute and capillary vessels. The 

 lungs are swollen — pulmonary cedema — of a dark colour, firmer 

 than natural ; the crepitant character which so distinguishes 

 healthy lung-tissue is not gone, but diminished — it feels to con- 

 tain more liquid than air. Although heavier than natural, its 

 normal elasticity and spongy texture are not so much destroyed 

 that it will not float in water, in this respect differing from 

 the consolidation of pneumonia, the condition of red hepatiza- 

 tion to which in many respects it bears a resemblance. This 

 state of splenization of lung-structure, as the result of pul- 

 monary engorgement has been called from its resemblance in 

 physical character to the spleen, has, when incised, a dark red 

 colour, with occasional spots of a deeper hue marking the 

 points of blood-eflusion, and from the cut surface there is an 

 oozing of bloody serous liquid mmgled with mucus, and 

 rendered frothy from the entanglement of air. The entire 

 structure is from the engorgement and distension rendered 

 more friable than natural, probably less so, however, than in 

 the more advanced stage of hepatization. 



The lining membrane throughout the entire tract of the air- 

 tubes, particularly the bronchi, is heightened in colour, and 

 covered Avith frothy mucus. 



In no parts do we find effusion, save of serous material ; the 

 characteristic plastic exudation of inflammatory action being 

 as yet undeveloped. 



In the examination after death of animals which have died 

 from pulmonary congestion, a mistake very commonly made by 

 non-professional observers is to regard the dark-coloured, 

 friable condition of acute engorgement, with its softened, damp 

 appearance tending to putrescence, as indicative of a diseased 

 condition of some time standing ; whereas we know that the 

 opposite is the direct conclusion to be drawn from these con- 

 ditions. Darkness of colour, with softness and liquidity of 



