CAPILLARY VESSELS IN INFLAMMATION. 333 



the capillary is increased, as in congestion. By the 

 long-contimied stretching or pressure to which these 

 deUcate nerve-fibres would be subjected, partial 

 paralysis would be induced. 



In inflammations and in the long-continued feverish 

 condition, the growth of bioplasm external to the 

 vessels, and which results from the m.ultiplication of 

 bioplasts that had traversed the capillary walls during 

 the stage of congestion, must seriously impair the 

 action of these nerve-fibres ; and there is good reason 

 to think that some of the phenomena that ensue are 

 the direct consequence of the nei've disturbance. 

 Let us, therefore, consider very briefly the changes 

 occurring in one of the slightest and most familiar 

 forms of inflammation — a common flea-bite. 



The tissues which are perforated by the cutting 

 instrument of the flea as it penetrates, would be, 

 first, the epithelium ; next, that modified connective 

 tissue with its "corpuscles" (masses of bioplasm) 

 of which the papillae and the most superficial layer 

 of the true skin consist. Embedded in this con- 

 nective tissue are certain vessels and nerves. The 

 following tissues would be more or less damaged by 

 the passage of any shai^p instrument through the 

 different layers of the skin, — cuticle, connective 

 tissue, the capillary vessels (lymphatics in some in- 

 stances), and nerves ; and these are the only tissues 

 which can be affected under the circumstances 

 allnded to. Now the capillaries, as we know, receive 

 blood from the arteries ; and the cahbre of the latter 

 vessels, and therefore, the quantity of blood travers- 

 ing them and the capillaries, is determined by the 

 state of the nerves which supply them, and the nervo 

 centres. 



Now, it will be noticed in a flea-bite or other in- 

 flammation of skin, that there is a certain blush 

 which is very deep in colour close to the wound, but 

 paler in tint extends a considerable distance around 



