238 VETERINARY PATHOLOGY. 



they occur. They may be of slight significance or may cause a 

 fatal termination, depending upon the importance of the vessel 

 and extent of the collateral circulation or anastomoses. These 

 calculi are usually composed of calcium compounds. 



ArtcrioUlhs are calculi formed in arteries. Their cause, for- 

 mation, composition and termination being practically the same 

 as that of phleboliths. 



Lithopcdia are calcified foetuses. In extra-uterine foetation the 

 foetus occasionally lives only for a short time. Dead extrauter- 

 ine foetuses frequently become impregnated with lime salts, 

 producing the so-called lithupedia. Lithopedia may also occur 

 within the uterus. This class of calculi is quite common in 

 swine and some cases have been observed in cattle and sheep. 



COXCREAIENTS. 



DEFINITION. 



ETIOLOGY. 



V.-IRIETIES. 



Hair balls. 



Fecal matter. 



Bile. 



Pus. 



Milk. 



Cerumen. 



Concremcnts arc accumulations of organic inaterial in the 

 cavities of holloa- organs. Their elTects are practically the 

 same as the eft'ects of calculi. Their formation depends upon the 

 collection and massing tugether of organic substances derived 

 either from the body in which the concrements occtir or from 

 some extraneous source, 'lliev may be homogeneous or hetero- 

 geneous in structtn^e : oval, spherical, or angular and faceted in 

 shape, variable in size, color and number, (STo oat hair concre- 

 ments were found in the great colon of a horse bv" C. Roberts, 

 !\f. R. C. \'. S.). Tltey mav be composed of hair, muctis, fecal 

 matter, casein, inspissated pus or bile, ingcsta of various kinds, 

 etc. 



Hair Balls (Egagaropiles) are accumulations of hair into 

 masses. They occur nirjst frequenth' in animals that lick them- 

 selves as the ox and deer. Other animals are affected as the hog, 

 dog and cat, also man, especiallv barbers, hair-sorters, hair-dresS' 

 ers, etc. Dr. A. Trickett observed a Persian cat that vomited 

 a mass of hair ^4-inch in diameter and 3 inches long. Egagaro- 

 piles vary in size from a pigeon's egg to a basket ball. They 

 are in some cases simply masses of hair in others thev are im- 

 pregnated and incrustecl with mineral substances, giving them 



