Trachelhm.'] infusorial animalcules. 569 



Genus TRAcnELius. The neck Animalcules. — Body ciliated, mouth 

 simple, destitute of teeth, upper lip very much elongated, in the 

 form of a proboscis. The last organ and the cilia serve for the pur- 

 pose of locomotion ; in three species, however, no cilia arc to be seen. 

 The mouth is seated at the base of the proboscis in four species. In 

 four species, also, the polygastric structure of the alimentary canal 

 has been demonstrated by coloured food, and in three the discharging 

 orifice ; but, from the rounding off of the extremities of the others, 

 the latter has only been presumed. In T. mclcagris the gall is of a 

 pale red colour. The propagating apparatus of two species is her- 

 maphroditic ; in the others it is only partially demonstrable. In T. 

 ovum and T. meleagris the expulsion of ova granules has been seen. 

 Two species increase by transverse self- division. 



The account given by Dujardin, of the animals of this genus 

 Traehelms, differs much from the foregoing. According to it, 

 Trachelius is destitute of a contractile, or reticulated integument ; 

 and is composed of a glutinous substance, containing granules which 

 are oftentimes agglomerated in the form of nodules, disposed in 

 rows. The oviposition, Ehrenberg believed he witnessed, in T. 

 ovum, and T. meleagris, was, according to Dujardin, nothing more 

 than the breaking up of part of the animalcule by 'diffluence,' and 

 the supposed ova only particles of ' sarcode.' 



" The cilia at the anterior extremity are larger than those on the 

 rest of the body. Posteriorly a large vacuole is often to be seen. 

 There is no distinct mouth." 



This genus Trachelius forms a member of the family ' Trichodiens,'' 

 (Duj.) along with Trichoda, and genera named Acineria, Pelecida, 

 and Dileptus. 



T. anas {Trichoda anas et index, M.) — Body Avhite, clavate, and 

 cylindrical ; proboscis thick, obtuse, and shorter than half the body ; 

 mouth situated close to the base of the proboscis. F. 287, 287''", 

 exhibit two full-grown Infusoria ; the former shows the current pro- 

 duced to bring the food within its reach ; f. 288 is a specimen under- 

 going transverse self-division ; and f. 289 a young one. Found in 

 exposed infusions, and amongst Conferva. Size l-280th to l-120th. 



T. vorax. — Body clavate, ovate, turgid, colour white ; thick obtuse 

 proboscis, shorter than half the body; mouth situated near the 



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