PARASITES OF ANIMALS. 137 



also in the arteries of the colon, coecum, small intestine, and 

 liver, as well as in the posterior mesenteric and renal arteries, 

 and others adjacent to the intestine. These tumors are gen- 

 erally fusiform, and as large as a man's finger; but they are 

 sometimes globular, and may become as large as a man's 

 head. The middle meml^rane of the artery in these dilations 

 becomes enormously thickened, sometimes being twelve times 

 as thick as in the healthy artery. In old tumors various hard 

 or calcareous deposits often take place in the thickened walls 

 or in the inner membrane ; and in such cases, the walls being 

 weakened, are liable to be ruptured by some unusual exertion 

 of the animal, when death results almost instantly. In the 

 interior of the aneurism there is generally a deposit of fibrin, 

 firmly adherent to the inner surface. In this and in the dif- 

 ferent layers of the walls the worms are found, — sometimes 

 only a few, but frequently large numbers. This disease is 

 very prevalent among old horses. In France, as many as 

 ninety-six out of one hundred have been found affected with 

 the disease. 



I am not aware that any remedies have ever proved useful. 

 Generally it would be impossible to detect the disease during 

 life, unless the tumors became very large. 



Sderostoma innguicola Yerrill. 



On two occasions I have received specimens of a rather 

 large parasitic worm, which lives in the fat of hogs. In the 

 first case, five specimens were obtained, at New Haven, by 

 Dr. M. C. White, from the fatty portion of a spare-rib ; in the 

 second instance, at Middletown, Conn., Dr. N. Cressy found 

 large numbers of the worms in the fat about the kidneys of a 

 young Suffolk pig, brought from New Jersey. Un- 

 .fortunately, none of these specimens are in so good a state 

 of preservation as to enable me to determine with certainty 

 all the points of their structure. Those which I owe to the 

 kindness of Dr. White, had been mounted in glycerine as 

 microscopic objects and pressed out flat, before they came 

 into my possession, and the tissues were thus injured and 

 the organs deranged. Those from Dr. Cressy, were both 

 pressed flat and dried. Yet by careful masceration, and 

 with much labor, I believe that most of the important char- 

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