594 



DISEASES OF THE SKIN. 



ADDENDA. 



CUTANEOUS AFFECTIONS OF BIRDS WHICH ARB 

 CAUSED BY ANIMAL PARASITES. 



Mange of Poultry. 



Acari hold the first place among the numerous parasites living 

 upon birds in poultry yards. They produce two principal kinds 

 of mange, 



1. Sarcoptic mange, produced by the Dermatoryetes mutans 

 (Ehlers), also designated under the names of Sarcoptes mutans 

 (Robin), Knemidocoptes viviparus (Furstenberg). 



2. Symbiotic mange, which is due to the Symbiotes gallinarum 

 discovered by Caparini. According to Trouessart and Neumann, 

 this parasite is said to be identical with the Epidermoptes bilobatus 

 (Rivolta). 



I. Sarcoptic mange. The Sarcoptes mutans was discovered 

 in 1859 by Reynal and Languetin. It resembles closely the sar- 

 coptes of mammals, from which it differs in some of its characters, 

 especially in the disposition of the mandibles. The females are 

 larger than the males (0.4 millimetre in length) ; the body is sphe- 

 roidal ; the males are rather of an ovoid form (0.2 millimeter in 

 length). They are of a dirty yellow color. These parasites are 

 provided with four pairs of legs in the adult state, and three 

 pairs when in the larval form ; the anus has two long hairs, one 

 on each side. It is a burrowing acarus, digging sub-epidermic 

 galleries. 



It is frequent upon the chicken, but we also observe sarcoptic 

 mange upon pigeons and exotic birds ; foreign gallinaceous races 

 are predisposed to it. Mégnin found it upon turkeys, pheasants, 

 and small pet birds. In 1885 Railliet described, in the pigeon, a 

 particular mange produced by an acarus related to Sarcoptes mutans, 

 and which he designated Sarcoptes lœvis, var. columbœ. Quite 

 recently he has found a second variety of the same acarus on the 

 chicken — Sarcoptes lœvis, var. gallinœ. The Dermatoryetes de- 

 scribed by Friedberger in 1886-87 is very likely identical with the 

 Sarcoptes lœvis, Raill. The fact of the great variability of these 

 parasites permits the supposition that Sarcoptes mutans and S. lœvis 

 constitute but two varieties of the same species. According to 



