PARASITES OF TRICHOSPOROSIS 671 



described in Europe in which the hair of the head and beard was 

 attacked. 



In trichosporosis the interior of the hair is never affected, but on the 

 surface the parasite forms irregular nodosities which more or less completely 

 surround it. 



These little nodosities consist of an amorphous substance containing short 

 or elongated cells which from mutual pressure are 

 polyhedral : after dissociation in potash the 

 greater number of the cells are seen to be placed 

 end to end in branched chains. In cultures on solid 

 media these cells elongate and form true filaments. 



Fungi of the genus Trichosporum grow easily 

 on agar, gelatin, broth, potato, Raulin's and 

 other media. 



Several species have been described : Tricho- 

 sporum giganteum, the cause of Piedra in Colombia, 

 which forms very firm nodosities (Behrend) ; 

 Trichosporum ovo'ides (Behrend), Trichosporum 

 ovale (Unna), Trichosporum beigeli (Beigel, Vuille- 

 min) found on the hair of the beard and moustache 

 in Europe. [Trichosporum krusi and Trichosporum 

 foxi are species found by Castellani in Ceylon.] 



SECTION IV. THE GENUS COCCIDIOIDES. 



These parasites are still little known. They were first found in man by 

 Wernicke in Buenos-Ayres in a case of dermatitis (cancerous dermatitis, 

 Guiart), afterwards by Rixford and Gilchrist in the United States, by Posadas 

 in Argentina and has also been seen in San Francisco. 



The disease beginning in the skin more or less rapidly infects the lymphatics, 

 becomes generalized, and after a variable length of time terminates fatally ; 

 it can be reproduced in mammals and birds by sub-cutaneous inoculation, 

 monkeys being very susceptible to infection (Posadas). In the neighbourhood 

 of the infected spots, the skin becomes covered with papules ; these unite and 

 form plaques the centres of which ulcerate and discharge a purulent fluid 

 containing numerous cysts ; in the glands and internal organs, the lesions 

 are similar to those in miliary tuberculosis. 



In the lesions of the skin the parasite is not found within the epithelial 

 cells but in tubercles similar to the tubercles of actinomycosis (giant cell 

 formation containing the Coccidioides and surrounded by epithelioid cells). 

 The parasite is present in large numbers in the pus. 



Blanchard considers that the various parasitic forms which have been 

 described are all identical (Coccidioides immitis), though other observers 

 regard them as constituting three different species. Blanchard originally 

 classified the parasite with the Coccidia among the Sporozoa. Since then, 

 however, Buschke, Ophiils, Cohn, have shown that it will grow on agar, 

 giving origin to mycelial filaments and budding forms : it therefore becomes 

 necessary to transfer the parasite to the fungi, and it is possibly closely allied 

 to the genus Oidium. 



C. immitis consists of spherical corpuscles, 20-80/x in diameter, enclosed 

 within a thick cuticle. It grows easily on agar and the cultures on inoculation 

 will infect susceptible animals. Both in the tissues and in cultures some of 

 the spherical bodies appear to contain spores which are set free by dehiscence 

 of the enveloping membrane. 



