BUREAU OF ANIMAL INDUSTRY. 



271 



a tough coriaceous capsule, Diesing placed iu it the StrongyJns tracheal** 

 of Nathusius under the name of Sclerostoma syngamvs. Finally Dujar- 

 din§ restored for this parasite the old genus JSyngamus of Siebold, and 

 gave it the old specific name of Syngamm trachealis of the same author. 

 Dujardin ascribes to the genus Syngamvs the following characters: 



"Worms ordinarily coupled in a permanent manner or by union of the integument? ; 

 the male, cylindrical, much smaller than the irregularly cylindrical female, with con- 

 stricted neck and tail tapering to a point ; head globular, large, supported by an in- 

 ternal corneous capsule ; mouth large, irregularly rounded, with six or seven broad- 

 ened lobes; pharynx provided with fleshy papilhe; integument folded or wrinkled 

 without regular stria,'. The male has a truncated tail, the latter provided with a mem- 

 branous expansion which fastens itself to the integument of the female. Tho female 

 has the tail conical, elongated ; vulva situated anteriorly at the base of the coustric- 

 tiou forming the neck ; eggs large, elliptical. 



The following, according to the same author, are tuo characters of 

 the only species, Syngamus trachcalis, which this genus includes : 



Body soft, colored bright red by a liquid interposed between the viscera. Male 4 

 to 4.5 mm (.157 — .177 inch) long; .4 mm (.016 inch) wide ; enlarged, obliquely truueated 

 head about .7 mm (.028 inch) broad. Tail terminated obliquely by a convex, unilate- 

 ral, membranous sac or bursa .25 to .3 mm (.009 to .012 inch) long, attached to the 

 superior border of the vulva of the female and supported by 12 to 15 equal rays. Fe- 

 male 13 rain (.512 inch) long ; .3 to l mm (.01 to .04 inch) broad, irregularly folded and 

 wrinkled; head 1.3*™ (.05 inch) broad; tail resembling au elongated cone; anus 

 1.2 mm (.047 inch) from extremity ; projecting vulva at the base of a neck 1.5 to 2 miu 

 (.058 to .08 inch) long, incliued to one side; eggs smooth, elliptical, .087 to .W3 mm 

 (.0034 to .0036 inch) long, with a short terminal neck. 



Dujardin found the Syngamus trachealU to the number of live pairs in 

 the trachea of two magpies (Corvus pica) at Rennes. He was able to 

 determine that even after maceration the male could not be separated 

 from the female without rupture of the integuments. 



This parasite has been found by Nathusius either in Germany or iu 

 England within the trachea of the following species : The swift {Cypse- 

 lus apus), the starling (Sturnus vulgaris), the green woodpecker (Picus 

 viridis), the pheasant cock (Phasianus gallns), and tbe black stork (Ci- 

 conia nigra), granting that it was the same species. 



What relation exists between the two parasites of the bird's trachea 

 spoken of above — the fasciola of Montagu, the cause of the gapes, and 

 the Syngamus of Siebold I 



Dujardin and Diesing regarded as entirely erroneous the classifica- 

 tion among the distomesof the parasite found by Montagu in the trachea 

 of birds affected with the gapes. This parasite was to them none other 

 than the Syngamus, but as they did not enter into any details concern- 

 ing the accidents which it is liable to produce, some doubts appear to 

 have remained in the minds of French helininthologists concerning this 

 assimilation. For we read iu M. Davaine's treatise on Entozoa (2d ed. 

 p. 37) the following statement concerning the parasites which cause the 

 gapes among the Gallinae : 



These entozoa, which for a long time have been referred to the distomes, are proba- 

 bly identical with the Sclerostoma sytiflamus, a nematode worm, to which the perma- 

 nent uuiou of male and female has given a particular physiognomy which has de- 

 ceived the earlier observers. 



The word " probably," iu the above extract well indicates that for M. 

 Davaine there was as yet no certainty that the gapes was caused by 

 the Syngamus trachealis ; there was only a probability. Moreover, in 



*Synops. pp. 414, 415. 



t Archivf. Naturgesch ich te, Wiegmann (1835), p. 1. 

 *L. c, 1836. 



$ Mistoire nat. das helminthes in suites a Buffon. Koret, Paris, 1645, p. 260. 



