CHAPTER III. 



DISEASES OF THE DIGESTIVE OR 

 CANS. 



A. Those caused by parasites. 



There are a great many parasites that iufest the di- 

 j^estive organs of fowls. Some of these are of but lit- 

 tle moment, because they occur in small numbers and 

 do but little harm; while others are of the greatest 

 consequence because they are sometimes exceedingly 

 numerous and seriously affect the health of the af- 

 flicted bird or cause death. The number of parasites 

 that sometimes infest fowls without producing appre- 

 ciable effects is almost incredible; while in other cases 

 a much smaller number of parasites of the same 

 species may not only cause great inconvenience but 

 may destroy the life O'f the infested bird. So it is evi- 

 dent that the effects of parasites depend not only upon 

 the number and activity of the parasites themselves, 

 but also upon the strength and resisting powers of the 

 bird affect<*d 



TTsually. Ilic nun.bc-r of fowls in a flock that harbor 

 parasites of the same kind is considerable. So that 

 when one (vf a tlock is killed by parasites, and the cause 



(52) 



