TKICHOPHYTON TONSUEANS. 143 



the second was " in diameter ; the many small scaly s'pots had 

 likewise grown larger. When the remainder of the hair, 1 2'" 

 in length and covering the scales, was plucked out and examined 

 under the microscope, these fragments of hair were seen, when 

 enlarged only 300 times, to be filled with spores between the hair- 

 fibres. The root of the hair presented a mouldy appearance. 

 The spores lie sometimes in the form of a necklace; sometimes 

 they represent articulated branches. When the hair is torn out, 

 fresh hair grows after some days, showing, however, the same 

 tendency to mould. Fragments of hair are seen in the scales 

 on the bald patches, bent and twisted in all directions, and the 

 spaces between the fibres charged, as if with spores. It is 

 probable that the lead-gray colour of these fragments of hair is 

 derived from their being mingled with scales. 



On considering the properties of the diseased hair more 

 closely, it is found that the root of the hair is at first, when it is 

 the exclusive seat of the disease, opaque, dwindling away, and 

 almost always bent, whilst the rest of the hair is quite healthy. 

 In proportion as the fungus developes itself in the substance of 

 the hair, the latter becomes thicker and coarser, grayish, and 

 opaque, loses its elasticity, becomes soft, and breaks, showing an 

 uneven filamentous fracture. The fractured pieces are full of 

 fungi, and remain covered with scales. If the hair breaks off 

 underneath the skin, the end of the capillary canal becomes 

 stopped up with scales and fat, which harden, and are at last 

 raised by the hair ; this has sometimes been erroneously mis- 

 taken for an abscess. With the decrease in the development of 

 the parasite, the hair becomes less gray, firmer, thinner, and 

 finally normal. If the head is kept clean, only a slight redness 

 of the skin, or small pustules or crusts are observed, which, how- 

 ever, rarely degenerate into impetigo. 



Want of cleanliness of the head makes the skin look like the 

 flesh of a hen or a shark. If no complication occurs at first, 

 only an increased formation of scales takes place, together with 

 the presence of fragments of hair, as in pityriasis, unaccompanied 

 by a falling off of the hair ; on the contrary, the latter generally 

 grows faster. The disease frequently attacks children who are in 

 good health. Sometimes the growth of the hair is seen to be less 

 strong before the breaking out of the disease ; the hair is dry, and 

 from this it may be inferred that a certain amount of disease of 

 the hair is necessary to the growth of the fungus. 



