PARASITOLOGY. 47 
THE ACARI. 
DERMANYssUS GALLINAE (Derma—skin; gallus—a cock). 
Synonym.—Chicken mite. 
fTistory.—Universally found in hen-houses. 
Description.—They are very small, as the word 
“mite” indicates. The body is ovi-pyriform in snape 
and broadest through the posterior third. The pierc- 
ing stylet is cone shaped, and on either side is a 
rounded palpus. The color of the body is yellowish 
red, depending on the amount of blood contained in 
the digestive tract. The legs are arranged on the 
anterior half of the body. 
Animals Infested.—Birds. 
Condition Produced.—They attack the birds in 
large numbers, piercing the skin and sucking the 
blood, and produce great irritation (pruritus). They 
may even cause death of the host. Infested set- 
ting hens may leave their nests. The parasites hide 
in the nests, and cracks and crevices of the building. 
If the nests are in the same building with horses or 
cattle, or if the birds so infested roost in the stable 
with larger animals, the mites may become tempo- 
rary parasites of the larger animals, causing pruritus 
and scratching, rubbing, rough coat, etc. 
Treatment.—Roosts, nests and buildings should be 
whitewashed with limewater to which has been add- 
ed creolin or kreso. The roosts should be drenched 
with kerosene. Pyrethrum and sulphur, equal parts, 
may be sprinkled in the nests two or three times a 
week. 
TROMBIDIUM HOLOSERICEUM (Trombos—harvest) 
(holo—whole.) 
