i68 



DISEASES OF SWINE 



tinguished from the female by its curved caudal 

 extremity. 



The ova, or egg's, are about one four-hundredths 

 of an inch in length. 



Source of Infection. — The eggs of the female be- 



FIG. 19 — COMMON ROUND WORMS 



come mixed with the alimentary matter and pass out 

 of the intestines with the excrement, and become 

 scattered over the pens and pastures. Infection oc- 

 curs by taking the eggs containing well-developed 



