254 THE MICROSCOPIST. 



serous catarrh ; into serous cavities inflammatory dropsy ; 

 into tissues, inflammatory oedema ; under the epidermis, 

 serous vesicles, etc. A serous exudation containing albu- 

 men is found in many inflammations of the kidneys (al- 

 buminuria), and of the intestine (dysentery), etc. 



Mucous exudation, or mucous catarrh, occurs oftenest 

 on mucous membranes, from the mingling of the epithe- 

 lial cells with the increased flow from the vessels. The 

 term " catarrh " came from the ancient idea that in a cold 

 liquid flows from the ventricles of the brain through the 

 ethmoid bone and nose. 



In catarrhal inflammation of the mucous membrane 

 there is first hypersemia, then swelling of the membrane 

 and lymph-follicles with an increased production of epi- 

 thelial and mucous elements. The excessive growth of 

 bioplasm in these elements, according to Beale, changes a 

 simple mucous catarrh into a purulent one (Fig. 203). 



FIG. 203. 



Catarrh (purulent) of conjunctiva, a. Epithelium. 6. Connective tissue stratum of 

 the mucosa. After EINDFLEISCH. 



In catarrhal (lobular or broncho) pneumonia there is a 

 proliferation of the alveolar epithelium of lobules or 

 groups of lobules connected with those bronchial tubes in 

 which the catarrhal changes first began (Fig. 204). 



If the patient recover, but the retained substances are 

 incompletely removed, a thickening of the walls may re- 

 sult, with the formation of a caseous nodule. 



