618 TRICHOMYCETES, ACTINOMYCETES, HYPHOMYCETES 
media. In this respect Achorion schonleinii differs culturally from 
the majority of molds. Material taken directly from the center of 
a scutellum, streaked upon agar, usually develops into white or gray 
colonies in which the mycelia and spores are readily recognizable with 
the lower powers of the microscope. Frequently adventitious organ- 
isms overgrow the more slowly developing favus parasite. If a piece 
of the scutellum is ground in a sterile mortar with sterile powdered 
water glass and the powder well distributed upon gelatin-agar or 
Sabouraud's medium/ pure cultures are usually obtained. The yellow- 
broMii colony usually exhibits a central depression resembling some- 
what that of the scutellum. The swollen ends of the filaments are 
quite characteristic. There appear to be several varieties of the mold, 
but there is only one type of the disease. ^ 
Herpes Tonsurans.— iievYies tonsurans, ringworm. Tinea tonsurans 
or sycosis is a disease chiefly of the hairs of the head or beard, but it 
often spreads to the skin as well, Tinea circinata. The axillary or 
pubic hairs are occasionally involved. It occurs in children rather 
more frequently than in adults. The disease is characterized clinically 
by the formation of inflamed scab-areas or patches on the skin imme- 
diately surrounding hairs and these patches exhibit a decided tendency 
to spread. They itch intensely and within them the hairs fall out. 
Usually the inflammation is not accompanied by exudation, but in 
very severe cases pustule formation may occur. The disease is con- 
tagious and is transmitted by towels, the hands, hairdressers' utensils 
and very commonly in the tropics through laundry. The initial lesion 
appears in the outer layers of the skin and extends downward through 
the hair follicle and then invades the inner layers of the hair itself, 
through which both the mycelia and spores develop in large numbers. 
The organism, Trichophyton tonsurans, was described by Gruby 
and by Malmsten in 1845. Several subvarieties have been described, 
but their differential characteristics are imperfectly established. It 
is readily demonstrated in the hair bulb by adding a few drops of 
NaOH solution, gently heating and examining under the microscope.^ 
The mycelial filaments appear in the bulb and penetrate for some 
distance along the hair shaft. The spores are usually restricted to 
the outer layers of the hair. 
The mold grows readily upon neutral agar and gelatin, the latter 
becoming liquefied. After a few days' incubation, multicellular 
mycelia with their nodal thickenings within which chlamydospores 
develop appear and frequently the colony becomes pigmented — 
1 Sabouraud's Medium: 
Peptone (Witte) 2.0 grams 
Glycerin, redistilled, pure .... 4.0 grams 
Water 100.0 cc. 
Agar 1.2 grams 
2 Kolmer and Strickler: Complement-fixation in Parasitic Skin Diseases, Jour. Am. 
Med. Assn., 1915, 64, 800. 
^ Water should not be added after the addition of the NaOH, else the hair will very 
quickly crumble. 
