LYMPHANGITIS. 89 



adapt them for nutritive purposes; man}' of these small lymph 

 vessels start from small points in the intestines and while the pro- 

 cess of digestion is going on take up portions of the imperfectly 

 digested material, called chyle, conveying it also along these tubes 

 and this in its course presumably becomes mixed with the water}' 

 constituents of the blood picked up b}^ these vessels in other parts 

 of the body. 



Now as these vessels (lymphatics) are found all over the bod 3', 

 generally in company with blood vessels, at all events in the legs 

 of the horse, it will be understood how it is that digestion is 

 considered to play so prominent a part in the production of lym- 

 phangitis (or weed). The ordinary constitutional symptoms 

 are very similar to those which present themselves in most febrile 

 diseases, but the distinguishing symptom is localized generall}^ in 

 the hind limbs, and consists of considerable swelling, which com- 

 mences in the groins, accompanied by extreme tenderness, which 

 gradually extends downwards to the hock and fetlock joints; 

 the swelling is produced by an exudation of fluid from the lym- 

 phatic vessels and the veins; and the anticipated result of admin- 

 istering a remedy for this condition is the taking up again of the 

 fluid on the part of the veins, that has passed through their walls 

 already and those of the lymphatics; it is perhaps necessary to 

 explain here that the walls of these lymphatic vessels and veins 

 are so constructed that under excessive pressure, brought on 

 under certain inflammatory conditions, the fluids contained are 

 able to pass out on a modifled principle of the sieve, and where 

 the fluid has passed out, it can of course pass in, provided the 

 necessary attraction is present to draw it in again; this attraction 

 is just the power that is wanting so long as the inflammation 

 exists; let that be allayed, and the conditions are altered, the 

 vessels are then capable of retaking up the fluid and passing it on 

 to its proper destination and the swelling subsides; but when the 

 necessary' remedy which is required to allay the inflammation is 

 not administered, and the vessels are not reduced to the condition 

 which enables them to reabsorb the exuded fluid, something has 

 to be done with this fluid, and nature has ordained that if not 

 removed it must be turned into something solid, and so a tissue is 

 formed which, if examined under the microscope, is found to con- 

 sist of the most minute fibres worked up into very beautiful mesh- 



