EXPLANATION OF THE PLATE. 



Fio. 1. Inner surface of split leather showing the cavities formed by the 

 enlarged hair-follicles. Six or seven of these cavities are filled with the seba- 

 ceous secretion. (Natural size.) 



Fig. 2. Cross-section of a piece of the untanned skin from which the hair 

 has been removed, showing one of the diseased follicles filled with fat. (Natu- 

 ral size.) 



Fig. 3. Cross-section of the same. The sebaceous matter has been removed 

 from the follicle. (Natural size.) 



Fig. 4. A similar section magnified, showing one of the infested follicles 

 together with four in the normal state. The light-colored bodies near the 

 surface of the skin are sebaceous glands. 



Fig. 5. Magnified section of a healthy skin from which the hair has not 

 been removed. 



Fig. 6. Demodex folliculomm from one of the infested hair-follicles, highly 

 magnified (Hartnack obj. 9, oc. 4). The annuli of the abdomen are too 

 strongly marked. 



Fig. 7. Anterior part of the same, much enlarged. 



Fig. 8. Egg of Demodex ? 



Fig. 9. The same, in which the yolk has shrunk away from the shell. 



