336 TWO SPECIES OP PARASITIC MITES. 



the rat, for instance, M. Megnin 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 

 Hering'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. Megnin, 

 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 diseased, 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 fceces, but a gi-eat 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 



