THE CHICKEN-MITE. 85 



minute nippers, and no eyes. Their legs possess seven joints, 

 and the tarsi have t^wo claws with a sucker bet^veen them. 

 Only two genera contain species that are parasitic upon 

 domesticated animals; these are Dermanyssus and Gamasus. 



THE CHICKEN-MITE OR "TICK." 

 {Dermanyssus gaUinm Redi.). 

 This mite infests domestic fowls, cage-birds, and hot in- 

 frequently torments man and beast. In extreme cases, or 



when very numerous, it has even 

 caused a form of phthiriasis, a 

 disease otherwise caused by the 

 presence of immense numbers of 

 sucking-lice. Three species have 

 been described, namely, D. gal- 

 luue upon chickens, D. avium 

 upon birds, and D. hlrundinis 

 upon swallows, but very prob- 

 ably they are all the same. The 

 Bird Tick {D. avium) occurs in 

 Fig. 50.- Chicken-mite or "tick." largc numbcrs in bird cages, and 



Enlarged. Original. => . 



is sometimes very annoying to 

 the birds, robbing them of their sleep, and if not removed 

 may cause their death. 



The so-called "tick" of chickens is very much larger than 

 all the other mites mentioned thus far, the male measuring 

 0.60 by 0.20mm., the female 0.80 by 0.28mm., and the ^gg 

 0.20mm. As seen in the illustration (fig. 50) the mite pos- 

 sesses eight legs, of which the first two are longest, not well 

 shown as the specimen were rather poorly mounted. The 

 mite is either blood-red, reddish-brown or whitish, the color 

 depending largely upon the last meal consumed. Chicken- 

 mites of this kind are most abundantly found in hen-manure, 

 or behind the frame-work of the hen-house. Large numbers 

 breed and hide in the nest of chickens, and if an egg should 

 be broken in such a place it is soon covered with myriads of 

 them. They occur also in bird-cages, pigeon-houses, and 

 nests of swallows or other birds. They attack also the skin 

 of man, horse, dog, cats, and other animals, where they 



