200 TAPEWORMS OF niRKSi AND 11 ABlilTS— STILES. 



aucl healthy ones, as well as those that were weak aud lean, disclosed the fact that 

 they were almost without exceptiou infected with tapeworms, which were found in 

 the duodenum and gall duct. In the latter they were frequently so numerous as to 

 close it up, aud cause a suspension of its functions. 



For the purpose of continuins; his studies Mr. Curtice brought from the West a 

 number of lambs, which were killed at intervals and their viscera examined, and 

 this material having been exhausted, and it being inconvenient and expensive to 

 obtain move, he turned his attention during the past winter to a study of the early 

 stages in the life of the I'wn'ia jiectlnata (common unarmed tapeworms of the rabbit). 

 In studying these Mr. Curtice thinks he has made some interesting discoveries, 

 Avliich he presented to the liiological Society of Washington at a recent meeting. 



The variety examined is found abundantly in nearly all ral)bits in this localitJ^ 

 The life-history of the armed tapeworms of man aud dogs has long been written, 

 but that of the unarmed species inhabiting our domestic aniuuils, espcicially cattle 

 and sliec]), is as yet comparatively unknown. As far as has been ascertained, the 

 life-history of the Tan'ui pevtiiiala is embraced in two stages. The first covers the 

 developuu'iit of the ova into th(^ embryo, which is ready to leave the parent Ttunia; 

 the other covers the period of growth Irom the youngest forms yet found in rabbits 

 to the adult stage. The life of the Twnia from the time they leave the first rabbit 

 as an embryo until they are found as young Twnia in the second rabbit infected has 

 as yet been unascertained. Among the theories that have been advanced is one 

 that they pass this stage upon the ground, are eaten by insects, snails, or crusta- 

 ceans, and that these are then eaten by the rabbits. This, however, is only a theory, 

 as none have ever been found in snails, insects, or crustaceans. 



Itwas ^Ir. Curtice's good fortune. to liiid a rabbit which had recently been infected 

 with these peculiar parasites, none of which were over H centimeters in length, 

 many of them being less than 5 millimeters long. There were more Tania in that 

 rabbit than any he had ever seen before — about 85. Among tin; smaller Tania w^ere 

 several specimens that showed the stages of devel<)i)ment from nonsegmented, armed 

 forms, to segmented, uiiaiuied Ibrms. Mr. Curtice showed to the society specimens 

 illustrating the ditferent stages. 



The youngest forms detected were not the smallest, but measured about one-half a 

 centimeter in length. They contained, in addition to the four suckers, a cup-shaped 

 cavity in the place of the rostellum. Around the border of this cup-shaped cavity 

 were situated 85 or 90 hooks. The older .specimens show a similar cavity with no 

 hooks. Still older ones show no cavity at all. All of these were in the nonseg- 

 mented stages, but other forms, some of them smaller, were without signs of hooks, 

 and had already begun segmentation. 



Mr. Curtice compared these stages wirli similar stages in Tunia serctla [ticrrata], 

 and said that the youngest stage of the Tnnia pecthiata was ])r<)baV)ly a cysticercoid 

 stage and not the cysticercal, aud that this was indicated by the cup-shaped cavity 

 in the youngest Ibrms of the Tinihi jxct'niata. 



In discussing the classification founded on the presence or absence of hooks, he 

 declared it to be incorrect, since the discovery described above shows that the 

 unarmed species in adult stages are armed in earlier stages. 



The speakia* exhibited some elegant drawings made by Dr. George Marx, illus- 

 trating the embryo as it leaves the parent Twnia. This embryo is six-hooked and 

 surrounded by a curious pyriform envelope, to which there is a double prolongation, 

 surmounted by a cap of the same substance. This cap has a shredded border, aud 

 is believed to be the remnants of a mass which, in an earlier stage, completely sur- 

 rounded the embryo. This ])eculiar envelope has been previously noticed in Italy 

 by I'erroucito [Perroncito] and in France by Raillet [KaillietJ. This stage is 

 similar to that found in Twnia cxpansa, the unarmed tapeworm in sheep. 



This article was copied in the Texas Live Stock Journal,' but, owing 



1 April 14, 1888. 



