WORMS, 213 



body, especially into those which carry blood to 

 the wall of the gut (particularly anterior mesenteric 

 artery). ^ At those parts of the arterial walls where it 

 collects in large numbers, swellings (aneurisms) are 

 produced, varying from the size of a pea to that of a 

 hen's egg. A constriction is often developed quite 

 close to this swelling, and a plug of fibrin may also 



Fig. 129. — Tail of male Strongylus cmnatus, strongly magnified. 



be formed within the artery, so that the circulation 

 in the wall of the gut is greatly hindered. As a 

 result of this the glands and muscles in the wall of 

 the digestive tube refuse their office, so that regular 

 digestion and onward movement of the food do not 

 take place. This leads to colic. As soon as the 

 strongyloid larvae have become adult, they pass from 



