APPENDIX 



TO THE CLASS OF INTESTINAL WORMS. 



THERE are certain worms which do not live in other animals, 

 >ut reside in water, or in moist earth, or in vegetable substances 

 undergoing acetous fermentation, and which, nevertheless, since in 

 brm and internal structure they correspond with Ascaris, Oxyuris, 

 or Filaria, appear to belong to the order of thread- worms. Some 

 )f them were by former writers arranged amongst the Infusories, as 

 species of the genus Vibrio. To these belong the minute animals 

 which LINNAEUS brought together under the name of Chaos redivi- 

 vum, and which were described and figured by MUELLER as varieties 

 )f one species, Vibrio anguillula (Animalcula infusoria, pp. 63-68), 

 though he doubted whether they ought not to be regarded as 

 different species of a genus for which he had altready proposed the 

 name Anguillula, by naming them Anguillula aceti, Ang. glutinis, 

 Ang. fluviatilis, and Ang. marina. The genus Anguillula was 

 afterwards adopted by EHRENBERG to distinguish these animals 

 rom Vibrio 1 . DUJARDIN named the same genus RJiabditis, but 

 assigned to it somewhat different characters. 



Anguillula EHRENB. (Rhabditis DUJ.) Body filiform, pellucid. 

 VIouth round, terminal, naked. Anus before the posterior extre- 

 mity, sub-terminal. The male with tail naked or amplified by a 

 membrane (alate). External genital organ a double spiculum. 

 Tail of the female conical, acute. 



Sp. Anguillula aceti G(ETZE Naturforscher xvm. Tab. in. figs. 12 18; 

 DUGES Ann. des Sc. not. ix. 18-26, PI. 47, fig. 2 : from i 2 millim. in size ; 

 these animals may be frozen without dying, whilst occasionally on the other 

 hand a slightly increased temperature affects them mortally. Another 

 species, Anguillula glutinis, lives in sour paste (MuELL. In/us. Tab. IX. 



1 Symbolce physicce, Pliytozoa, and Organisation, systematic und geographisches 

 Verhaltniss der Infusionsthiercken, Berlin, 1830, s. 68, 105. OKEN in his Lehrb. der 

 Naturgesch. in. i, 1815, s. 191, places these animals under the genus Gordius, yet 

 in the index he keeps Anguillula as the name of a genus, (see s. 847). 



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