117 



in it, but niimerous scars of T. marginala furrows on the surface of the liver. It was 

 also found that nuuierous white patches, which were scattered along the mucous 

 coat cf the small intestine, were due to a species of coccidia. As the latter disease 

 has not been seen since that time, and as there was a possibility that the lamb had be- 

 come infected with the coccidia from the dirt thrown out of noigliboring rabbit pens, 

 where the disease was abundant, it has not since been studied. The results, so far as 

 T. expansa is concerned, were negative. 



October \Q. — A ewe lamb was examined which had died some hours previously ; but 

 one cysticercus was found. 



October 15. — A young buck lamb was examined, which was bought in May with his 

 mother, soon after birth, from a neigliboriug slaughter house and was one of those 

 which is referred to as raised on the place). There were found a quantitj'^ of youug 

 ta'iiiae, many adult and young of Strongylua contortua, a few youug Dochmius, and a 

 few Trickocephahis. This lamb was one of the two that was dreuched with eggs ou 

 May 16. He had pastured with the others, which it was subsequently learued had 

 adult la'nia, and which had been purchased supposing them to bo infected. 



October 9. — A buck lamb was examined, one of the six purchased in May. Old 

 cicatrices of Tccnia marginata were found in the liver, six Ci/sticerci of this species, 

 two adult and six youug Tcvnia expansa, a quantity of youug and old Slrotujyhis con- 

 torting, and a few specimens of Trichocephahis. 



October 16. — A buck lamb, another of thesix, was found to be infested by a quantity 

 of very youug iteuia, also by young aud old StrongyJus contortiis, Dochmius, and Tri- 

 chocephalns. 



October 17. — Another of the six animals bought in May was fouud to contain youug 

 aud adult Tania expansa, Strongylas contortus, Dochmius, aud Trichocephalus. 



January 3, 1889. — A lamb slaughtered for examination was found to contain three 

 Twnia expansa, one Cysticercus, and mauy specimens of Strongylus filicollis. 



The period which bad elapsed from the time that these lambs had been 

 reeeiv^ed on the place, to the period when the majority were examined 

 (from May to October), was about five months. Those first killed gave 

 negative results, probably because they were examined too soon after 

 feeding. The lot examined in October gave very positive results. 

 The worms found in them varied from very young to adult. The small- 

 est and youngest are those shown on Plate XV, figs. 8, 9, aud 10. These 

 were not fed t-o the sheep, for lambs which had not been fed were in- 

 fected ; but the majority of the 3'oung tapeworms were acquired and 

 developed after the sheep came under the experiment. This is amply 

 proven in the case of the young buck bought and put with its mother in 

 the experimental yard before the former was two days old. That the 

 time of development of the adult worm is less than four months was also 

 proven, from the fact that other lambs, less than four months old, ex- 

 amined in May at the slaughter house, contained adult tape-worms. 

 The lambs, therefore, acquired those parasites on the place. The ques- 

 tion t)f the necessity of an intermediary host is also settled by this ex- 

 periment, for none of those invertebrates, which are usually suggested 

 as being the intermediary bearer, were present at any time ; nor were 

 the conditions which are essential to the life of many such invertebrate 

 hosts present. The pasture was and is a very dry hillside yard, from 

 which the grass was eateu very close by the sheep. 



There is another phase of the question which is stillin doubt. Early 



