276 ON DEMODEX PHYLLOIDES. 
ous abscesses. As the parasite is confined to the skin, and does not 
appear to affect the general health of the animal, he has merely 
ordered the removal of the skin from the parts involved, a precaution 
which is entirely sufficient to render the flesh useful for food. 
My observations have served to establish the complete agreement 
of my specimens with those of Csokor. I have accordingly concluded 
that a synopsis of his paper, which is probably accessible only to a 
few of those who may be interested in the matter, with a copy of his 
excellent figures, may stimulate enquiry into the distribution of this 
parasite in America, and perhaps into the means best adapted to 
hinder its attacks becoming so formidable as represented by Dr. 
Csokor. 
Dr. Csokor’s paper considers : 
1. The history of hair-sac mites in general. 
2. Their systematic position. : 
3. The natural history of D. phylloides in particular. 
4, Its occurrence and mode of life. 
1.—Sprcies or DEMODEX occur in the sebaceous glands and hair 
follicles beside the nose in man, occasion forms of mange in dogs 
and cats, and have been recorded (but merely in isolated cases) from 
the sheep, horse, ox, and Surinam bat. The best known forms have 
been distinguished by Megnin as three varieties : 
D. folliculorum hominis. 
D. folliculorum canis. 
D. folliculorum cati. 
A good many experiments have been made with a view to ascer- 
tain whether the Demodex of the dog is capable of being transferred 
to man, and vice versa, and although some results appear to render 
likely the possibility of both methods of transference taking place, 
yet the weight of evidence unquestionably points the other way. 
The mode of occurrence of the Demodex of the dog is so totally 
unlike that of the Demodex of man, that apart from difference in 
form and size, we would be inclined to suspect a difference of at any 
rate varietal value. In man the Demodex is found on the hairless 
parts of the face and is perfectly harmless, in the dog it is found in 
the hairiest parts and brings about a troublesome and often fatal 
cutaneous disease. Experiments, however, as to transference can 
hardly be depended upon, for although it is quite certain that the 
