Inflammation. Phlogosis. Phlegmasia. 47 



undergo cloudy swelling and are often detached, allowing the 

 readier migration of the globules through the openings of the 

 lymphatics and the softened and friable walls. When the capil- 

 laries are blocked the pressure necessarily increases on the arterial 

 side, favoring laceration of the friable walls and the escape of 

 minute masses of blood. The formation of the buffy coat is char- 

 acteristic of the normal equine blood ; in inflammation it becomes 

 more abundant. In the other genera a buffy coat apart from in- 

 flammation may be shown in : (a) anaemia or oligocythsemia in 

 which the blood is deficient in red globules ; (b) in plethora in 

 which there is an excess of blood solids ; (c) in pregnancy in 

 which there is an excess of white and small red globules ; (d) in 

 violent exertion or over-excitement, in which the blood has circu- 

 lated with extraordinary rapidity. The all-sufficiency of the tissue 

 cells in determining inflammation may be deduced from the fol- 

 lowing experiment. A ligature is tied around a frog's thigh so 

 tightly as to arrest circulation, and the leg amputated above the 

 ligature ; mustard is then applied to the web of the foot and a 

 blister rises precisely as though circulation continued. 



MICROBES, DIAPEDESIS AND PHAGOCYTOSIS. 



The r61e of microbes in inflammation is much greater than 

 was formerly supposed. It is now demonstrated that a large class 

 of inflammations are directly caused by the colonization of mi- 

 crobes in the tissue and by the local irritation caused by their 

 ptomaines and toxins. We must also admit the direct action of the 

 latter on the heat producing and vaso-motor nervous centres, as 

 a factor more or less potent in different cases in the causation and 

 maintenance of inflammation. No less important is the relation 

 of the microbe to the migration of the globules and the subsequent 

 results of the inflammation. This influence microbes share with 

 certain chemical agents. Migration may be greatly checked even 

 in inflamed parts by the hypodermic or intravenous injection of 

 sulphate of quinia, eucalyptol, salicylic acid, or iodoform. Some 

 have thought these acted by a chemiotactic attraction, but quinia 

 is otherwise found to repel the leucocytes. Their action on the 

 leucocytes or capillary walls is problematic. 



Chemiotaxis is that power by which a microbe or any element 



