1116 The Hair-Sac Mite of the Pig. [ November, 4 
Csokor has studied the locomotion of the mites in a drop of 
oil on a hot stage, and finds the movements which are, at the 
ordinary temperature, so sluggish, become then so energetic that 
he considers the want of success of various experiments as to 
infection to be due to the absence of a sufficiently high tempera. 
ture. He calls attention to the fact that the disease has been 
rapidly spread over the surface in a dog by the use of warm 
water in washing affected spots, and that probably also the raising 
of the temperature of the skin by the rubbing in of ointments 
may contribute to the spreading of the parasite. He found that 
the pedipalpi are particularly active in locomotion, and are able 
to bore into a soft surface. : 
Only the two terminal joints of the legs take part in locomo — 
tion; the head may be moved from right to left and also upward a 
and downward—the combination of these movements resulting : 
in a rotation of the head upon the thorax. The abdomen may 
be also flexed against the thorax in very active locomotion. 
The eyes, which appear very early in development, are | 4 
tute of pigment in the adult, and are situated upon the dorsal 
surface near the mandibles. oe 
The male is shorter than the female; the appendages of the 4 
mouth are less developed; the abdomen is less than half the A 
length of the body ; between the anal opening and the end of a 1 
sternum are two curved chitinous pieces which represent * q 
penis. a 
The female is at once distinguished by the longer abdomen sz - 
the three-sided structure which it contains, and which 1s pee 
ally discharged through the fissure behind the sternum a5 ] 
egg; the oviposition has been observed by Megnin. a 4 
Csokor has traced the occurrence of three molts, the first ae i 
tween the egg and the six-footed larva, the second pee i 
six-footed and the eight-footed larva, the third between the ee a] 
footed larva and the adult. ntt 4 
Csokor concludes his observations by describing the M® 
ae 
The hair-follicles in these localities a eted 
sebaceous gland. Fig. 3 represents a section through an # 
