CEOUP. 565 



secretion, and the consequent formation of false mem- 

 brane. 



"The cadaveric lesions will vary according to the mode 

 of death ; when the animal dies asphyxiated during a par- 

 oxysm, there will be the congested lungs and the general 

 appearance characteristic of death beginning at the lungs ; 

 when the patient, on the other hand, dies, in a comatose 

 condition, from the venous character of the blood, the en- 

 gorged venous system and other accompanying effects will 

 be manifest. To pass over all these, it may be said that the 

 truly characteristic lesions are those of the mucous membrane 

 of the respiratory passages. This expression in reference to 

 the respiratory passages is employed advisedly, inasmuch as 

 genuine croup is understood to be confined to these passages ; 

 it may extend to the fauces, but never, like thrush and 

 diphtheritis, spreads to the mouth, the pharynx, or the 

 oesophagus. These morbid conditions consist in the presence 

 of false membranes of a greyish white colour, though some- 

 times yellowish or brownish, from a certain amount of colour- 

 ing matter of the blood. These productions are most frequent 

 in the larynx, though they are by no means confined to that 

 structure ; they extend, in many cases, into the trachea, less 

 frequently they are found on the fauces, while, in a certain 

 number of cases, the bronchial mucous membrane itself is 

 affected. They bear some analogy to the false membranes 

 found in inflammation of the pleurae and of other serous 

 membranes, but are nevertheless essentially different. Pleu- 

 ritic exudations have a plastic or formative power, by virtue 

 of which they become organized, and may remain as fibrous 

 bands or layers permanently attaching the costal to the 

 pulmonic pleurae. The false membrane in croup, on the 

 other hand, has never been known to become organized; 

 though it adheres firmly to the mucous membrane, the en- 



