66 . ENTOZOA. 



According to the description of Dnjardin, as abridged by Cams,* 

 the intestine of Oxyuris curvula is " filled with vegetable remains, 

 which it finds in the alimentary canal of the horse, and which it re- 

 duces by the help of its oral armament. There stand three cross 

 horny bars at the entrance of the mouth, which latter in the 

 middle bears a conical hairy papilla, and on the side two or three 

 furcated bristles. The oral aperture, which is surrounded by 

 muscular fibres that stand perpendicularly upon its walls, and 

 which is widened in front and behind, has a three-sided prismatical 

 cavity, which is fined by a resisting membrane. Behind the 

 horny bars there stand cross-folds beset with horny points. The 

 middle narrower part has folds still higher, which at the hinder end 

 make room for a row of closely-packed little folds, working like a 

 file." As regards the nervous system, if Walter's remarkable 

 description is correct, we have here a most complicated arrangement 

 of cords and ganglia. In the first place a series of ganglia, con- 

 stituting the so-called brain, which transmit filaments to the 

 oesophagus and mouth as well as numerous connecting twigs to 

 another set of gangha on either side of the body. These lateral 

 ganglia are also serially united by longitudinal cords, so that we 

 have in fact three long trunks traversing the greater part of the 

 body from end to end, the whole being united into one nerve- 

 system by numerous transverse connecting filaments given ofi" by 

 the central ventral cord at tolerably regular intervals. The ventral 

 cord itself is formed by two threads passing off" from the upper 

 part of the lateral cords a little below the oesophagal division of the 

 cerebral ganglia. These form a single median trunk which divides 

 in the region of the generative pore, so as to encircle the aperture, 

 and again uniting passes downward to the anal opening, where it 

 divides to form another complex series of caudal ganglia. Ulti- 

 mately the divisions reunite below the anus, and forming a single 

 true caudal or azygos ganglion, pass in the condition of a narrow 



* " Jahresljoriclit iibor die im Gebicte der Zootomio erschiencnen Arbciten." 1856. 



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