THE PATHOGENIC FUNGI 999 



and of Stavino on the production of tuberculoid lesions by intravenous 

 injections of cultures of these fungi have little significance in view of the 

 fact that many types of foreign bodies produce similar results when so 

 introduced. 



Immunity. Jadassohn 37 has noted that patients who have re- 

 covered from deep ringworm infections seem immune from subse- 

 quent attacks. A number of experimental observations especially 

 those of Bloch and Massini 88 and of Kusunoki 39 bear this out. It 

 appears that animals which have been infected with the more 

 virulent types which produce suppurative lesions resist reinoculation 

 and that the protection is valid against other species than those 

 first injected. On the other hand both clinical and experimental 

 observations show that infections with less virulent species induce 

 no immunity. 



All attempts to immunize animals by the injections of killed cultures and 

 extracts have failed. The reports 40 on the favorable therapeutic action of 

 vaccines are inconclusive on account of the variable course of the disease. 

 Plato 41 was able to produce in patients with suppurative ringworm both 

 cutaneous and generalized reactions by the injection of extracts of trichophyton 

 cultures. Skin reactions have also been obtained in animals and seem to be 

 nonspecific in regard to the species of fungus concerned but are, as a rule, 

 seen only in animals with those more severe infections which confer immunity. 

 Kolmer and Strickler 42 report that serum from ringworm cases gives comple- 

 ment fixation with extracts of cultures but that the reactions were again 

 not highly specific as to species. 



Methods of Examination. The demonstration of the spores and mycelium 

 in lesions is most readily made by placing the infected hairs or scrapings 

 from the skin in caustic soda or potash and covering with a cover slip. The 

 alkali renders the hair and epidermis transparent but does not attack the 

 fungus and renders it easily visible. (A satisfactory solution for this purpose 

 is a mixture of equal parts 30 per cent aqueous sodium hydroxide and 

 glycerin.) 



It is possible to stain the parasites with borax methylene blue and by 

 modifications of Gram's method, but none of the staining methods suggested 



37 Quoted by Sabouraud. 



38 Bloch, B., and Massini, E., Ztschr. f. Hyg., 1909, Ixxiii, 68. 



39 Kusunoki, F., Arch. f. Dermatol. u. Syph., 1912, cxiv, 1. 

 4(1 Strickler, Jour. Am. Med. Assn., Ixv, 225. 



"Keported by Neisser, Arch. f. Dermatol. u. Syph., 1902, lx, 65. 

 ** Kolmer and Strickler, Jour. Am. Med. Assn., 1915, 



