RECENT WORKS ON THE ENTOZOA. 339 



helmintliological studies, the best connected account which the 

 English language affords of the general history of the Entozoa, their 

 classification, external aspect, structure, habits, and development, 

 with special reference to those forms which occur in man. 



Very different in its nature is the work on Human Parasites by 

 Eudolf Leuckart, who is well known as one of the most learned 

 zoologists in Germany, and who, apart from his many other original 

 investigations, has taken a position in Helminthology scarcely in- 

 ferior to that of Siebold. "We need only refer to his treatise on the 

 Cystic Worms* in proof of this assertion. Leuckart has, in truth, 

 given the best account of the formation of the toenioid scolex from 

 its embryo. And he has also usefully exteoded the experiments of 

 Kiichenmeister and others on the strange wanderings of the Cestoidea 

 in general. He is the only naturalist who has hitherto investigated 

 with success the life-history of the AcantJiocepliala. Eurthermore, he 

 has thrown light upon the structure of certain parasitic forms not 

 included among the Helminths, alike in his admirable memoir on 

 Fentastoma,-\ and in his short account of the Faramecium coli of 

 Malmsten. 



The first volume of Leuckart's work is n ow before us. It con- 

 tains an introduction, of nearly 130 pages, on the general natural 

 history of parasites. A few pages follow on the parasitic Protozoa 

 of man. Eut the greater portion of the volume is devoted to the 

 human Cestoidea, Trematoda, and Leeches. These last, it may be 

 said, occupy a curiously intermediate position between parasitic and 

 non-parasitic animals. A second volume will be devoted to the 

 Nematoidea, and to the parasitic Arachnids and Insects. 



Although Leuckart's treatise is not ' got up' in the same luxuri- 

 ous style as Dr. Cobbold's, it is, nevertheless, well printed and 

 copiously supplied with woodcuts. Most of these are original. The 

 book, moreover, derives a classical character from the circumstance 

 that the author has prefixed to the first volume a portrait of the 

 illustrious Eudolphi, — pupil of Linnseus, and teacher of the scarcely 

 less celebrated Johannes MiiUer, who wrote an able and affecting 

 eloge in praise of his deceased master. Creplin, in 1829, dedicating 

 to Eudolphi his ' Novse Observationes de Entozois,' justly styled him 

 " Princeps Helminthologorum." 



* Die Blasenbandwurmer und ihre Entwicklimg, 18.*) 6. 

 t Bau und Entwicklungsgeschichte dev Pentastomen, 1860. 



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