TEICHINOSIS. 



69 



The ova soon hatch in the alimentary canal of the host, and 

 the larvae derived from them commence to lay eggs about six or 

 seven days after their entry. Often by the second day after 

 ingestion the larvse commence to mature; by the fourth day 

 they become mature. The young worms when they come 

 from the ova are extremely minute cylindrical bodies, only 

 Tj-Vifth of an iQch in. length. They soon commence to bore their 



14 -vd. 



Fia. 25. — Tbichina sfibalis. 



A, Piece of diseased pork (much enlarged) : en, cyst ; c.c, capsule : w, encysted worm. 

 B, Larva, c, Male. D, Digestive and sexaal organs of S (after Colin) ; oe, oesophagus ; 

 mi, mid-gut ; r, rectum ; T, testis ; vd, vas deferens ; c, cloaca. 



way through the walls of the intestine and enter the sarcolemma 

 of the muscles, penetrating into the primitive bundles, the sub- 

 stance of which degenerates, whUst a rapid increase of the nuclei 

 may be seen to take place. Sometimes the larvae are carried 

 along in the blood. At first the young lie straight in the muscles, 

 but in about two weeks they form a kind of citron-shaped capsule 

 in which they coil themselves up (fig. 25, a). This capsule is 

 derived from the degenerating connective tissue of the muscle 



