2^2 Inflammation. 



within tlie corneal mass. The leucocytes which escape from the 

 blooci vessels at the corneal border find their way along the spaces 

 of the corneal tissue to the point of injury and there collect about 

 it. This can be observed in the frog's cornea which has been 

 touched with a corrosive, if the animal be killed a day or two later 

 and the excised cornea spread out on a glass slide, as the leucocytes 

 of this cold-blooded animal retain tlieir motility for a considerable 

 time. The wandering cells are found elongated and conforming 

 in shape to the narrow tissue spaces, their presence giving the cor- 

 nea a milky cloudiness. At the same time the corneal cells are 

 found proliferating; they undergo division and become slightly 

 motile in response to the chemotactic agent connected with the 

 inflammation. If the inflammation continue for a comparatively 

 long time, eventually the marginal vessels begin to send vascular 

 buds into the cornea ; these may penetrate so far that the cornea 

 becomes covered or completely penetrated by a network of vessels, 

 a pannus ( •v tti^j/tj, a cloth). This proliferation is also, according 

 to Ribbert, probably due to a chemotactic stimulus affecting the 

 endothelial cells. The opacity which involves the cornea in the 

 course of the process mentioned may entirely disappear with the 

 completion of repair; the transparency returns because the cells 

 creep back and the fluid washes out the products of disintegration 

 and the capillaries undergo regressive changes. In other cases a 

 whitish scar remains as a remnant of the proliferated tissue. 



Inflammation of the cardiac z'ah'cs, according to Ribbert, is not 

 attended by penetration of leucocytes into the tissue at all ; aside 

 from the formation of adhesive clots, which develop upon the 

 roughened (from endothelial lesion) leaflet, the only evidence of 

 reaction consists in a multiplication of the fixed cells of the endo- 

 cardium and, in case the process continue for a time, of the pene- 

 tration of the capillary vessels from the base of the valve into its 

 substance. 



Anatomical Types of Inflammation and Exudation. — lExudation 

 of blood plasma, emigration of leucocytes and sometimes diapedesis 

 of red cells occur in varying degree, depending upon the causes of 

 the inflammation, its duration and local conditions ; and give rise 

 to special appearances which form the basis for differentiating a 

 number of forms of inflammation and exudate. 



The volume of exudate varies within wide limits ; it may be so 

 small that the inflammatory focus can be found practically only 

 with the aid of the microscope, or there may be such a quantity of 

 fluid that many liters may be removed (from the larger cavities of 



