THE MANGE OF THE HORSE. 59 
that of the female from 0.40 to 0.48 mm.; the former is 0.39 
mm. wide, the latter 0.835 mm. The eggs measure 0.17 mm. 
The illustrations (fig. 30, male and fig. 31, female and 
egg) were made from specimens which infested some hogs in 
the vicinity of the State Experiment Farm. Thelegs ofthese 
animals were in a terrible condition, showing that mites had 
been permitted to inhabit them for a long time. The strange 
and ridiculous thing about this case was the fact that the 
hogs were condemned to be killed as suffering from hog 
cholera. | 
THE MANGE OF THE HORSE. 
(Sarcoptes scabiei var. equt). 
This itch-mite is found upon the horse, ass, and mule, but 
can also migrate to man where it will thrive as well. 
Though very small it can be readily detected moving among 
the scurf of an infested skin if a strong magnifying lens 
is used. Like the other true itch-mites it forms small 
galleries beneath the scurf-skin, in which it hides and 
multiplies. If the hide of an infested horse is warmed 
by the sun, or in a warm stable, the mite becomes very 
active, and is found quite readily by those trained 
in such work. Prof. Law writes that to obtain speci- 
mens “it may be needful to tie the scab on the human 
arm till a prickling is felt, when the acarus will be found in 
the centre of a minute papule caused by its bite.” The writer 
did not think it absolutely necessary to offer his arm for such 
a purpose, and this accounts for the fact that no illustration 
has been made of this parasite. Perhaps some reader may 
be inclined to offer his assistance, and after isolating the 
mite in the above manner to donate it to the writer so that 
a picture can be made. 
Like all true burrowing itch-mites they can not exist for 
a long time if removed from their burrow and exposed to the 
dry air; in moist places they can exist, however, for many 
days, even for several weeks. 
Horses, etc. invaded by such parasites show the presence 
of them by their restlessness, which is caused by their inces- 
sant itching about the heads, manes, tails and backs. Here 
