354 INFLAMMATION. 



tion (Urzeugung), which means a new formation of cells from a liquid con- 

 taining no cells. 



The reason for the dilatation of the capillaries, observed in the stage of 

 .stasis of the blood-current, was at that time a question much discussed, but 

 never satisfactorily answered. Briicke's view that the capillaries, after a few 

 intense contractions, became paralyzed was accepted as the most probable. 

 The newly formed cells of the effusion, according to the theory of humoral 

 pathology, gave rise to new tissues as well as to the formation of pus. The 

 exudate itself was thought to become organized, and to produce pseudo-mem- 

 branes or hypertrophy of the inflamed tissues. 



C. Rokitansky * afterward changed his views concerning the origin of the 

 inflammatory new formation. This great observer announced, in contradiction 

 to the views of Virchow, that, in inflammation, proliferation comes not only 

 from " connective-tissue cells," but also from " intercellular substances " ; that 

 the latter also increase and give rise to new formations. It will be shown later 

 that this view, at that time not understood, is entirely correct, and that since 

 1873 we have obtained facts which establish it on a firm foundation. The 

 theory of humoral pathology was shaken by E. Virchow.t This investigator 

 asserted that the blood-vessels take but little part in the inflammatory 

 process. He based his conclusions upon observations made by His in the 

 inflamed cornea, and the observations of Eedfern in inflamed cartilage, both 

 tissues having no blood-vessels, yet becoming greatly changed by inflamma- 

 tion. The only active parts of the connective tissue, according to Virchow, 

 are the cells, which, after attracting the exudation from the blood-vessels, 

 being over-nourished, enlarge, divide, and subdivide, and finally give rise to 

 the inflammatory new formation, from which originates new formation of 

 connective tissue, hyperplasia, as well as pus. The theory that cells arise 

 from a plasma was no longer maintained. Virchow held that an exudation 

 could never organize a tissue, and that all new cells must necessarily be the 

 offspring of former ells. The new formation of cells, according to Virchow, t 

 starts from the nucleus, which is first divided, and the " cell-body" is after- 

 ward split up into new cells. 



The cellular pathology was based on these fundamental assertions of 

 Virchow, and it is certain that the great progress made in biological knowl- 

 edge in our day originated from these views, which gradually became the 

 leading ones, and are so even at the present time. That the cellular patho- 

 logical views are, however, not fully correct, I shall endeavor to demonstrate 

 later. 



J. Cohnheim, in 1869, announced a new theory regarding the inflam- 

 matory process, founded upon the fact that in the exposed mesentery of the 

 frog an emigration of colorless blood-corpuscles takes place from the capillary 

 blood-vessels and the smallest veins. The history of the theory of the emi- 

 gration of blood-corpuscles from blood-vessels is briefly as follows : 



Waller, || in 1846, was the first who maintained having actually observed 



' " Ueber das Auswachsen der Bindegewebssubstanzen u. die Beziehuug desselbeu zur 

 Eiitzundung." Sitzungsber. d. Wiener Akad. d. Wissensch., 1854. 



' Ueber Parenchymatose Entziindung," Virchow's Archiv, Bd. iv., 1852. 



t " Ueber die Theilung der Zellenkerne," Virchow's Archiv, Bd. xi. Cellularpathologie, 

 1871. 



t " Ueber das Verhalten der flxen Bindegewebskorperchen, bei der Entzuiidung." 

 Virchow's Archiv, Bd. xlv. 



|| Philosophical Magazin. Two successive publications : 1846, I., p. 271 and 397 ; II., 

 p. 398 et seq. 



