THE CHICKEN-MITE. 85 
minute nippers, and no eyes. Their legs possess seven joints, 
and the tarsi have two claws with a sucker between them. 
Only two genera contain species that are parasitic upon 
domesticated animals; these are Dermanyssus and Gamasus. 
THE CHICKEN-MITE OR “TICK.” 
(Dermanyssus galline Redi.). 
This mite infests domestic fowls, cage-birds, and not 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, ). gal- 
line upon chickens, DP. aviwimn 
upon birds, and PD. hirundinis 
upon swallows, but very prob- 
ably they are allthe same. The 
Bird ‘Tick (JD. aviwm) occurs in 
Fig. 50.—Chicken-mite or “tick.” large numbers in bird cages, and 
Enlarged. Original. 5 

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 egg 
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 
