Phenomena of JitHainmation. 



263 



flowing manner until the whole cell is on the outside. In the living 

 specimen all of the steps of the passage, so like a creeping move- 

 ment, ma}' be followed ; and in sections of an inflamed tissue cells may 

 be found partly outside and partly within the vessels, fixed in their 

 constricted condition and reminding one very much of the appear- 

 ance of a wasp with its abdomen constricted from the thorax. Some- 

 times these cells show a long stretched out protoplasmic process, 

 swollen out into a button in case a part of tlie substance with the 

 nucleus has moved forward. The leucocytes which have escaped 



Fig. 49. 



An inflammatory focus the seat of cellular infiltration in tlie tissue of the kidney. 



(Section of the kidney of a cat.) 



from the vessels continue their creeping movement and thus dis- 

 tribute themselves in the spaces and interstices of the tissue of 

 the inflaminatory area between the connective tissue cells and fibril- 

 lary bundles, and wandering on between the epithelial cells to the 

 free surface of the part. 



As new cells are constantly passing from the vessels the inflamed 

 tissue becomes thickly studded with leucocytes, constituting a con- 

 dition known as eelhilar infiltration.' A number of authors believe 

 that the leucocytes after their egress from the vessels multiply in 

 the tissues by amitosis (direct division), and, too, that the lymphoid 



