WEED. 



507 



extremities — is peculiarly dependent on exercise. Hence, the probable reason 

 for lymphangitis appearing in the extremities ; for its selecting the hind limbs 

 in preference to the fore ones ; and for its being induced by idleness and high 

 feeding. Why it should occasionally occur, as it is said to do, while an 

 animaf is in a starving condition, though doing no work at the time, is some- 

 what difl&cult of explanation. Perhaps the lymph, when no food has been 

 aiven for some time, becomes abnormally rich in nitrogen. I can offer no 

 explanation as to the preference exhibited by this disease, according to good 

 authorities, for the near hind leg, rather than for the off one. 



Fig. 146. — Ulcerative lymphangitis. 



Owing to the existing inflammation, a large quantity of fluid escapes from 

 the vessels into the adjoining tissues, and gives rise to the swelling. This 

 fluid has a strong tendency to become consolidated unless it is promptly 

 removed by the lymphatics and smaller veins, whose power of doing so is 

 held in abeyance as long as they remain inflamed. Hence, the advisability of 

 reducing the inflammation as quickly as possible, and of endeavouring to 

 prevent its recurrence. 



The fact that two other kinds of lymphangitis (pp. 503 and 505) 



