AND PHE LOWER ANIMALS. 209 



Cercarise were the larvae of the latter. From this 

 period the history of the group became clearer. In 

 1850, Van Beneden' s very important memoir ap- 

 peared, in which, on the support of direct observa- 

 tions, he asserted that the cystic worms were 

 nothing less than the scolices of the cestoids.* And 

 shortly after, this novel but important fact having 

 been demonstrated experimentally by Ktichenmeister, 

 was published as one of the results of his first ex- 

 periments. In 1853, these two writers, in competing 

 for the Academy's prize, completed their former 

 researches, each regarding the subject from his own 

 stand-point, and confirming the other in many im- 

 portant particulars. Yan Beneden, moreover, treated 

 of the Trematodes and other groups. Since that date 

 new facts have been announced. Grastaldi,t Filippi,J 

 Siebold,§ Moulinie,|| and others, have added to our 

 knowledge of the Distomidae ; and Lewald, Siebold, 

 Wagener, % Van Beneden, Leuckart, La Vallette, and 

 others, have repeated and extended Kuchenmeister's 



* " Les Vers cestoides ou Acotyles, considered sous le Eapport 

 de leur Classification, de leur Anatomie et de leur Developpement." 



t " Cenni sopra alcuni nouvi Elminti della Eana esculenta." 1854. 



J "Memoire pour servir a l'Histoire genetique des Trematodes," 

 in the "Memoires de rAcademie de Turin," 1854. This memoir is 

 reproduced in the "Annales des Sciences naturelles," fourth series, 

 vol. ii. Second memoir on the same subject, 1855 ; third memoir, 

 1857. 



§ "Memoire sur le Leucochloridium," 1854; "Memoire sur la 

 Eeproduction des Helminthes en general," 1854, translated in the 

 ^ Annales des Sciences naturelles," 1855. 



|| "Dela Eeproduction chez les Trematodes endo-parasites," in 

 the " Memoires de l'lnstitut G-enevois," 1856. 



^T " Die Entwickelung der Cestoden nach einigen Untersuch- 

 uncren." 1854. 



