^0 Professor Miiller mi the Life and Writings of' 



one another than Cystica are like the Cestoidea. The long 

 tape- worm-shaped species of the Cysticercus {C. Jlisciolaris), 

 form the passage from the Cestoidea to the other Cystica. The 

 heads of the Coenurus and Echinococais are tape-shaped ; and 

 the Tetrahyncha, placed under the Cestoidea, have, apart 

 from the consideration of the proboscis, a considerable resem- 

 blance to the Echinococcus, although they do not live in ve- 

 sicles, and degenerate in vesicles. Hence Wiegmann has al- 

 ready remarked, that the animals of the Cystica tribe are re- 

 petitions of the Botriocephali (Grubenkopfe) and Taeniae 

 (BandwUrmer), and are to be regarded as undeveloped forms 

 of the same. According to my opinion, the Cestoidea and the 

 Cystica must be included in the same order, and form two dif- 

 ferent sections. What is known of the development of the 

 Taeniae is favourable to this arrangement; for, according to 

 Mehlis, several Taeniae, at an early stage, consist only of a head 

 portion. This apparent connection, which proceeds from the 

 arrangement of the members, may be strongly or faintly ex- 

 pressed in the two sections. In the Taeniae, it has relation to 

 the multiplication of members and the sexual portions. Some 

 animals of the Cystica section, on the contrary, as the Coenurus 

 and Echinococcus, appear as really compound animals, with a 

 common origin (" Blase'''' or vesicle), and many heads. 



If we can now explain more readily these connecting cir- 

 cumstances, we owe it to Rudolphi. He introduced order and 

 method into this new Fauna of nature, — inasmuch as he inves- 

 tigated and defined, in all its relations, an almost new region of 

 natural history. It is seldom that Germans, in their home un- 

 dertakings, have had the good fortune to investigate the natu- 

 ral bodies of foreign countries. Forster, Pallas, Lichtenstein, 

 Tilesius, and Kuhl, went to a distance, when they attached 

 themselves to undertakings connected with foreign countries. 

 The limitation caused by our geographical position, has, on the 

 other hand, imparted to our spirit a certain direction towards 

 what is concealed, and has made us so much the greater in the 

 investigation of a world of concealed inhabitants of our native 

 creatures, viz. the Entozoa, — in the investigation of the struc- 

 ture of natural bodies, and of their internal living processes. 



In his natural-historical writings, Rudolphi united the me- 



