418 INFLAMMATION. 



blood-vessels, on the contrary, and a breaking up of their endothelia into 

 medullary elements, afterward pus-corpuscles, takes place whenever the 

 tissue is destroyed by suppuration. Pus is mainly a product of the inflamed 

 tissue itself, and not of emigration of colorless blood-corpuscles. 



4. INFLAMMATION OF EPITHELIA AND ENDOTHELIA. 



Epithelia and endothelia, being formations of living matter, 

 respond in a very active manner to irritation. The changes of 

 this tissue are not primary, as the inflammation invariably starts 

 from the subjacent vascularized connective tissue. Even in mild 

 cases of inflammation in connective tissue, the presence of an 

 exudate can be demonstrated, which constitutes the condition 

 known as "oedema." The surplus nourishing material is carried 

 into the epithelia and endothelia from the blood-vessels, even 

 though the irritating agent should be brought in direct contact 

 with the epithelial or endothelial investment. 



The inflammatory changes in this tissue, as in every other, 

 consist in an increase of the living matter j the elements become 

 what is termed " coarsely granular," or assume the " condition of 

 cloudy swelling." If the inclosing shell of cement-substance is 

 not immediately liquefied, a marked endogenous new formation of 

 corpuscles takes place, resulting in the appearance of the so-called 

 u mother cells" i. e., bioplasson bodies, containing a varying 

 number of inflammatory elements, in all stages of development. 

 We can trace the new formation of these elements from the coarse 

 granules to the large homogeneous lumps, and, finally, to the 

 nucleated plastids (see page 46). If, on the contrary, the cement- 

 substance is liquefied in the early stages of inflammation, the 

 living matter herein present i. e., the connecting filaments 

 (" thorns v ) is enlarged, and shares in the new formation in 

 the same manner, as observed within the epithelial or endothelial 

 elements. First, a number of these elements coalesce, and form 

 large clusters of bioplasson, containing a varying number of 

 nuclei and a large quantity of coarse granules, which, passing 

 through the phases of bioplasson development, result in the 

 production of inflammatory corpuscles. The final result of the 

 inflammation is different, according to the plastic or formative, 

 or the suppurative nature of the inflammatory process. 



In plastic inflammation, the newly formed medullary or in- 

 flammatory corpuscles remain interconnected, and, becoming 

 fusiform, give rise to new formation of connective tissue. The " cirr- 





