344 Veterinary Medicine. 



of the intermediate host of the taenia, that which harbors it in its 

 cystic or larval condition. That such a host exists, follows from 

 the fact, that all true tape-worms, the full life history of which is 

 known, pass through the larval and mature conditions respective- 

 ly in two different hosts. This is fully confirmed for the ta£nia 

 fimbriata, by the complete failure of Curtice to convey this para- 

 site to lambs by feeding them with the ripe proglottides obtained 

 from mature sheep. When the progress of investigation shall 

 reveal this intermediate host, we shall probably see the way to a 

 perfect and easy prophylaxis, by the destruction of the host of 

 the larva, or by keeping it apart from sheep and from grounds 

 and drinking places frequented by sheep. In the meantime and 

 until such discovery shall be made, we can still apply some 

 rational, though necessarily imperfect measures of prevention. 



The pregnant ewes, and particularly ewes and lambs should 

 not be allowed on pastures which have been stocked by sheep the 

 year before. The host of the proscolex, must be taken in by the 

 sheep with its food or water and therefore presumably belongs to 

 some species of small invertebrate animal (Mollusc, Crustacean or 

 other), which lives in water, on fresh vegetation or in the damp 

 surface layers of the soil. These invertebrates as a rule have but 

 a .short lease of life and undergo a metamorphosis preliminary to 

 passing the winter. The cystic tapeworm is therefore, probably, 

 only entertained by such invertebrate for a few months, and when 

 set free by its death or metamorphosis, it too must perish unless 

 it can find its way into its next destined ho,st, the .sheep. One 

 year's absence of the sheep, or of the unknown host of the cystic 

 worm, from the pasture, and the taenia must perish for want of 

 the appropriate host in which alone it mu,st pass the next stage of 

 its existence. Of course, deer, and any other host of the adult 

 tape-worm must be equally excluded with the sheep. Fencing 

 the land into two or more enclosures, one of which shall be kept 

 free from sheep, deer, and the drainage of sheep pastures or deer 

 ranges for at least one year before the lambs are admitted to it, 

 must be among the most important measures of prevention. 

 When possible the lambs should be excluded from damp places, 

 and from the whole pasture when soaked by a prolonged rain- 

 storm and when they would tear up the vegetation by the roots 

 and eat it with the adherent earth and invertebrate life. They 



