36 



THE MICROSCOPE. 



nimble in its motion covered with short hairs 

 having a short head a pair of strong mandibles 

 and eight legs terminating in remarkable ap- 

 pendages each provided with a sucker. It has 

 no eyes but when disturbed it quickly draws in 

 its head and feet and then somewhat resem- 

 bles the tortoise in appearance; its march is 

 precisely that of the tortoise. It usually lays 

 si.xteen eggs which are carefully deposited in furrows under the skin 

 and ranged in pairs; these hatch in about ten days. 



Hogg describes the Demodex Folliculorum as follows : 

 '•it is another remarkable parasite found beneath the skin of 

 man ; it is sometimes obtained from a spot where the sebaceous 

 follicles are abundant such as the forehead the side of nose 

 and lip. If the part where a little black spot is seen or a ])ustule 

 be squeezed rather hard the oily matter there accumulated will 

 be forced out in a globular form; if this be laid on a glass 

 slide and a small quantity of oil added to it to cause the sepa- 

 ration of the harder portions the parasite will in all prob- 

 ability float out after the addition of a little more oil. It can be 

 taken away from the oily matter by means of a fine pointed sable 

 pencil brush and transferred to a clean dry slide. 



By far the most diliticult cases however are vegetable parasites 

 which cannot be found except by high powers. Of these we have 

 many species the habitat of which must be considered as well as the 

 special parasite in order that we may not be in error /. c, those 

 which inhabit the appendages of the skin, follicles, hairs, nails, etc. 

 Those which grow upon the integument pe?- se. I will now take up 

 in detail, such cases as have come under my observation. A (ierman 

 woman of 26 having with her two children in like condition with 

 herself came to my clinic. Her head was covered with an offensive 

 crusting; the hairs were broken and dry. She had suffered from this 

 for many years. I removed some of the crusts and sent them to Dr. 

 John H. Lobdell ''Instructor in Microscopy at Michigan College of 

 Medicine, for examination to aid in diagnosis, and received the fol- 

 lowing rei)ly. 



Fi,.\T Rock, Mich., May 12, 18S1. 

 I received from I'rof. Yemans April 14th, 1881, a few scales 

 supposed to be from a case of favus, with the request that I would 

 make a microscopical examination and report to him before his next 

 clinic ho-ir. 



