Phenomena of I)ifIaim)iatioii. 



261 



irritants. Thanks to the studies of Mrchow, Recklinghausen, 

 Cohnheim, Ziegler, Alarchand and others, the various steps which 

 develop and take part in the process in inflamed tissues have come 

 to be well understood. Only in connection wnth relatively unim- 

 portant questions do there still exist differences of opinion and theo- 

 retical discussions, involving- for instance such points as whether 

 the proliferation attending inflammation is produced by excess of 

 nutrition or lack of tissue tension, whetlier it may be assumed or 

 not that there is a functional stinmlation to excite cell formation, or 





Fig. 47. 



Emigration of the leucocytes in frog's mesentery, six liours after exposure. Tlio 

 cells shaded with lines are the red corpuscles ; the stippled ones are tlie 

 leucocytes; X 2511. (After I'erls.) 



whether certain granular changes of the cells should be spoken of as 

 inflammatory or regarded as degenerative. 



The inflammatory process ma}^ be directly traced (Cohnheim's 

 experiment*) under the microscope in transparent inflamed living 

 tissue, as the mesentery of a frog or rabbit, or in the expanded 

 wing of a bat or the tongue of a frog drawn out from the mouth 

 or in the web of a frog's foot, the inflammation being excited in 

 such tissue by the application of a caustic or the production of a 

 minute traumatic lesion. 



The first step of inflammation in a vascular tissue consists of 



*For details cf. Kitt. Baktoirnkinulc uiul pathol. iitlkruskopic ju>' Tier'drzte. 

 IV Aufl. W^en, M. Perles Verlag, 1903. 



