INFLAMMATION. 319 



material, which ended in becoming dissolved or caseous, and 

 never in being developed into connective tissue. Notwithstand- 

 ing his arguments, this misconception held its ground, until 

 Roldtanski's teaching, to which allusion has been already made, 

 paved the way for our present doctrines as developed by BiiJd. 



In accordance with their researches, we must divide the layer 

 of exudation, which lies loosely on the serous surface, into two 

 strata : 1. An upper one which, during the height of the in- 

 flanuiiatory process, assumes a disproportionate thickness ; this 

 layer really does consist of fibrin, and covers in the subjacent 

 one at every point. The fibrin accumulates in greatest 

 amount on those parts of the affected organ which undergo most 

 displacement, as e.g. on the free borders of the lungs ; just as in 

 whipping the blood to free it from its fibrin, the latter coagulates 

 in flakes upon the stirring-rod. The appearance of the exuded 

 fibrin under the microscope has already been described (§ 269). 

 It forms the same coarse network as in primary adhesion 

 (§ 271) ; it differs however in not being of i\\Q same thickness 

 throughout, varying in this respect from a quarter of a line to 

 six lines or more. 2. A deeper stratum of young connective 

 tissue formed by a proliferation of the connective tissue of 

 tlie serous membrane. We may assume that as soon as the 

 serous surface is denuded of its epithelium, the inflammatory 

 action extends into the connective-tissue layer of the serous 

 membrane; but without attaining any considerable intensity 

 till from the third to the seventh day of the disease. On 

 examining sections, we find a number of connective-tissue 

 corpuscles in the parenchyma of the serous membrane ; their 

 numbers increase as we approach the surface on which they are 

 set free. Upon this surface they appear embedded in a clear 

 matrix, containing mucin, together with which they make 

 up the layer of embryonic tissue which we are now considerino-. 

 Both cells and matrix must be viewed as a true efflorescence 

 from the serous membrane ; the true '^ plastic exudation " is 

 really formed by them, and not, as used erroneously to be 

 supposed, by the fibrin. 



§ 274. As regards the external form of this recent " connective- 

 tissue efllorescence," we need only remark that for obvious 

 reasons, it cannot arrive at any independent finality. Judgino- 

 from the analogy of recent layers of embryonic tissue occurring 



