The Muscles and Their Work. 31 



known as joint oil (synovia). It has already been stated 

 that this fluid is present at the joints, being secreted 

 from the lining of the capsular ligament, besides these 

 locations it is also found in little bags or sacs (bursae) of 

 shapes varying with the location, placed between a ten- 

 don and bone or between two tendons. From various 

 causes resulting in over-stimulation of the secreting 

 membrane, an overplus of this fluid is secreted, thus 

 accounting for swellings in various parts, of which bog 

 spavin and wind puffs are familiar illustrations. 



