336 TWO SPECIES OF PARASITIC MITES. 
the rat, for instance, M. Mégnin has found a species of Sarcoptes 
which differs considerably from the one on the cat, but which he has 
shown to be only a variety of the same species, therefore we retain 
Héring’s name cati for the variety from the cat, and adopt the name 
muris for that from the rat. 
This little parasite first attacks the cat at the base of the nose, 
around the eyes, and at the base of the ears, where it forms small 
white pustules in which the mite may be found. From these points 
it spreads over the whole head, then it is stated to work backwards 
over the neck, and finally over the whole body, reducing the poor 
animal to the last stages of leanness and decrepitude. M. Mégnin, 
however, states that the mite does not attack any other parts of the 
body, except the head and neck. As I have not had any opportunity 
of observing cats which have been a long time cliseased, it is impossi- 
ble for me to say at present which of these statements is correct. 
It has been asserted by some authors, who have no doubt drawn 
their conclusions from analogy to Sarcoptes scabiei rather than from 
direct observation, that this mite bores long and tortuous passages 
through the skin among the roots of the hair, but an examination of 
the diseased parts shows, not a number of winding passages filled 
with eggs and foeces, but a great number of round, cell-like cavities, 
in which the adult female is lying surrounded by several eggs and a 
quantity of foecal matter, showing clearly that the mite has been in 
this nest for a considerable time. The male and young are not 
found imbedded in the tissue, but scattered through and under the 
scab and on the surface, when the copulation evidently takes place. 
After impregnation the nymph then bores into the tissue, takes on 
the form of the adult female, and lays her eggs in the nest which she 
hollows out for herself. In parts of the animal which have been 
long affected, these nests are packed together so closely as to be 
almost in contact. 
It only remains for us to mention some of the remedies which 
have been recommended for the cure of this disease, always, however, 
bearing in mind the fact, that on account of the excessive sensitive- 
ness of the skin of the cat, many of the washes and lotions, which 
would be exceedingly useful when applied to other animals, would 
in this case probably prove hurtful or even fatal. 
Sulphur is the most generally useful insecticide, and where the 
mite can be reached by it, there is no doubt but that it will effect a 
