PLATYHELMINTHES 167 



Family II. Amphistomid^ 



Amphistomum cervi {A. conicum) is a species belonging with this 

 family not infrequently found in the rumen of domestic ruminants of 

 this and other coimtries. Specimens collected in the Pennsylvania State 

 Laboratory measure 6 to 7 mm. (3/16 to 1/4 of an inch) in length. The 

 body is conical in form, thick, attenuated anteriorly, gradually en- 

 larging posteriorly, the posterior end being obtuse and a little curved 

 ventrally. The mouth is terminal and surrounded by a small sucker. 

 At the thickened posterior extremity there is a second and much larger 

 sucker. The color is white or reddish, darker at the attenuated anterior 

 portion. Hermaphroditic; genital orifices ventral and median, situated 

 in the anterior third of the body. Its development is not known. 



This fluke is a parasite in the rumen of the ox and other domestic 

 and wild ruminants. It fixes itself by means of its posterior sucker 

 between the papillae of the rumen. Being very easily overlooked in its 

 resemblance to the papiUse, it is quite probable that it is more prevalent 

 than would appear from our present records. 



The parasite has been considered as inoffensive to the health of the 

 host animal. 



Control of Fascioliasis 



In sections where fascioUasis has appeared a prophylactic measure 

 of first importance is the avoidance of pastures which are wet or contain 

 collections of water affording habitation for snails. The following direc- 

 tions formulated by Thomas — as stated by Neumann — for limiting the 

 ravages of fascioliasis are here quoted in part: 



"a. Destroy the diseased sheep and bury them. 



"b. Only put on dry pastures affected sheep intended for the butcher, 

 as the fluke ova they evacuate cannot develop in the absence of huniidity. 



"c. As hares and rabbits — which are sometimes bearers of distomes — 

 may infest pastures, they should not have access to those on which 

 sheep graze. But this recommendation cannot weU be carried out. 



"d. Drain wet pastures, or, if this cannot be accomplished, dress 

 them with salt or lime. The latter in solution — 0.75 per cent. — will 

 destroy fluke embryos as well as the snails. With regard to salt, we are 

 indebted to Perroncito for some precise notions as to its action. Erco- 

 lani had for a long time observed that water slightly impregnated with 

 salt killed the cercarise, and in acting on these and on the encysted 

 larvae of the Limncea palustris, Perroncito found that in a 2 per cent, 

 solution these parasites died in less than five minutes; in a 1 per cent, 

 solution they rolled themselves up at the end of two to seven minutes, 

 and perished after twenty to thirty-five minutes. The same happened 

 in 0.64 per cent, solutions; and in those of 0.25 per cent, they were still 



