180 INSECTS AFFECTING DOMESTIC ANIMALS. 
in the dead specimens, this is withdrawn so as to appear simply as a 
part of the end of the tibia, and the spines located on its margin appear 
to belong to the tibial rim, but if examined with sufficient magnification 
when the louse is alive it is easy to observe the extrusion of the organ. 
Whether similar organs exist in related species is yet undetermined, 
but it seems quite probable that they should, since in the specimens 
examined microscopically we have usually to deal with dead and pre- 
served individuals in which this structure would almost certainly 
escape notice. 
The eggs are one millimeter and a half in length (0.06 inch) by three- 
fourths of a millimeter in width (0.03 inch). They are light yellow or 
dusky whitish in color, and taper slightly to the point of attachment. 
The circular lid-like portion is large, occupying nearly all the surface 
of the free end of the egg. They are attached usually near the base of 
the hairs. 
On account of the thinness of the hair the application of remedies, 
where necessary, is quite easy. Washes of tobacco water or dilute 
carbolic acid, and the application of kerosene in lard, or kerosene 
emulsion by means of a force pump, sulphur, ointment, ete., are recom- 
mended. The application of fine dust may be provided for naturally 
by allowing the hogs a chance to roll in a roadway or any place 
well supplied with fine dust. Where this is impracticable the dust, 
ashes, or powdered charcoal may be applied directly to the neck and 
back of the infested animal. The species is not known to attack any 
other of the domestic animals, and hence no precautionary measures in 
this direction are necessary. 
THE SUCKING HORSE LOUSE. 
(Hematopinus asini Linn.—macrocephalus Burm.) 
Notwithstanding the probable frequent occurrence of this species, we 
have as yet failed to meet with it in any abundance, ~ 
The biting lice from horses have been secured in 
great numbers, but we have searched in vain for 
this one, and but few have come to hand. 
It is figured by Redi (Exp., Pl. XXII, fig. 1), 
and was described by Linnieus under the name of 
Pediculus asini; presumably his specimens were 
taken from the ass. Later Burmeister described 
specimens from the horse under the name of Pedi- 
culus macrocephalus. Denny retains the name 
given by Linnzus and states that it is common 
upon the ass, and that he also had specimens from 
the horse, from which circumstance he suspected 
Burmeister’s macrocephalus to be the same _Gie- 
bel and Piaget both follow the name of Burmeis- 
ter, and Piaget separates as a variety the form occurring on the ce 
and gives it the name of colorata. 
Fie. 103.— Hematopinus 
asini (from Comstock). 
