117 



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

 also found that numerous white patclies, 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 witb the coccidia from the dirt thrown out of neighboring 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 10. — A ewe lamb was examined which had died some hours previously ; but 

 one cyslicercus was found. 



Octoier 13. — A young buck lamb was examined, which was bought in May with his 

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

 which is referred to as raised on the place). There were found a quantity of young 

 tceniae, many adult and young of Strongylus contortun, a few young Vochmius, and a 

 few Trichocephalns. This lamb was one of the two that was dreuched with eggs on 

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

 adult ioinia, and which bad been purchased supposing them to be infected. 



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

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

 two adult and six young Twnia expansa, a quantity of ^ouug and old Strongylus con- 

 tortiis, and a few specimens of Trichoce2>halu8. 



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

 of very youug Iceiiia, also by young aud old Strongylus contortiis, Dockmius, and Tri- 

 clwceplialiis. 



October 17. — Another of the six animals bought in May was found to contain young 

 and adult Toinia expansa, Strongylus contortus, Dockmius, and Trickocephalus. 



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

 Twnia expansa, one Cysticerctts, and many specimens of Strongylus fiUcoUis. 



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

 received on the place, to the jteriod when the majority were examined 

 (from May to October), was about live 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, and 10. These 

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

 fected ; but the majority of the young 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 tliose parasites on the place. The ques- 

 tion of 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 eaten very close by the sheep. 



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



