CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 107 



peculiarity of a male united permaueutly to a female, says, concerning: 

 the parasite under discussion, page G : 



Among the nematodes of the genus Syngamus the male lives attached to the female 

 hy means of a caudal sucking disk and twines himself about her as does the male of 

 Hedruis. 



This last statement italicized contains an error which proves that M. 

 Perrier had not yet seen the syugames in the position which they occupy 

 in the trachea, for the male is never coiled about the female, as we will 

 show further on, and as we have enabled M. Perrier to demonstrate for 

 himself. 



We are now permitted to say, after having studied the gapes in the 

 various pheasantries of central France, and the environments of Paris, 

 where this terrible epizootic has claimed thousands of victims, that we 

 know positively that the parasite which causes it, the so-called forked- 

 worm, or red worm of the pheasant breeders, is none other than the 

 Syngamus trachealis, and by no means a distome ; we know that it cor- 

 responds entirely with the general characters traced by Dujardin and 

 Cobbold, if we except a considerable number of anatomical and physio- 

 logical details which we have to add or to rectify, and its migrations 

 and habits which have thus far remained wholly undescribed. There 

 was complete ignorance of its mode of development, reproduction, and 

 its transmigrations. All these we have been able to follow experiment- 

 ally or in the poultry-yards, and hence to deduce the most rational in- 

 dications to combat the gapes successfully and to arrest its spread. 

 Experience has fully confirmed our deductions. 



ZOOLOGICAL AND ANATOMICAL DESCRIPTION. 



We must, at first, rectify the diagnosis of the genus and species as 

 given by the authors, because it appears to us faulty, especiallj" in 

 that which refers to the mouth-parts. We present the following diag- 

 nosis of the genus : 



Mouth large, supported by a hollow, hemispherical, chitinous capsule, 

 its background furnished with six or seven chitinous, cutting papillaj ; 

 border thick and turned back (reirows«e),cutinto six symmetrical lobes, 

 united to the integument by its entire external face, and furnished ,by 

 it with four equal membranous lips, which form a prolongation to the lobed 

 border of the capsule. To this they are united by four bands, which 

 attach the commissures of the lips to the four deeper notches between 

 the lobes of the capsule. Female fixed by its mouth to the tracheal 

 uuicous membrane of its host ; the male likewise attached by its mouth 

 to the same mucous membrane and united immovably by its caudal 

 bursa to the vulva of the female, around which it is soldered, as it were. 

 The two spicules equal, contiguous, extremely fine, and very short. 

 Ova provided with a valve at each end of the longer axis. • The eel-like 

 embryos are developed within the uterus of the female whence they 



