A EEVISIOK OF THE ADULT TAPEWOKMS OF HAEES 



AND EABBlTri.i 



By C'h. Waedell Stiles, i'b. D., 



Honorary Viislodlau of the Mclmintholoyical Collection, l\ S. National Alimcuni. 



A DISCOVERY by Cooper Curtice in 1887 regarding certain young 

 stages of ral)bit tapeworms, observations wbicli I was able to conlirm 

 and extend in 1894, immediately brought the lejjorine cestodes into 

 a very important position, viewed from an economic as well as from a 

 scientific standpoint, for Curtice's observation at first sight seemed to 

 offer a guide to solving the puzzle as to the larval stage of the tape- 

 worms of cattle, sheep, horses, and certain other animals. 



Curtice observed in the intestine of rabbits certain young cestodes 

 which bore minute hooks ui)on the rostellum, and older stages were 

 found which had lost these hooks. He determined the adult cestodes 

 found in these rabbits as Tamia pectiHata and looked upon the armed 

 forms as the young of this species. 



With these observations before us, it looked as if some very radical 

 changes would be made in the near future in the classification of the 

 tapeworms of the larger domesticated animals; it further seemed prob- 

 able that the young stage- of the tapeworms of cattle, sheep, and horses, 

 would eventually be found to be an armed cysticei'coid. 



In a paper- in 1891 I called attention to this bearing of the question 

 and extended Curtice's observations. I found that the suckers'^ as 

 well as the rostellum were armed, and that the head bore a remarkable 

 resemblance to the head of Darainea. This complicated the question 

 in so far as to render necessary the consideration of two further i)os- 

 sibilities — i. e., were these young cestodes the early stages of avian 



'At the request of the author, it is here stated that he is not responsible for the 

 insertion of commas between the names and the authorities, and for the absence of 

 capitals at the beginning of specitic names derived from personal names. These 

 changes have been made in order to bring his paper into conformity with the usages 

 at present followed in the U. S. National Museum. — Editor. 



-Notes sur les Parasites — 31 : line phase precoce des Tenias du Lapin, (Notice pr6- 

 liminaire), Bull. Soc. zool. France, 1894, XIX, pp. 163-16.5. 



^Some old sketches of Curtice's show that he also observed the hooks upon the 

 suckers. 



Proceedings U. S. National Museum, Vol. XIX— No. 1105. 



145 



Proc. N. M. vol. xix 10 



