BLASTOMYCETES 385 



as due to a member of the mold genus Sporotrichum. The organ- 

 ism described by Tokoshige should be reinvestigated. It is pos- 

 sible that it may prove to be a Sporotrichum also. 



Distribution. The disease is known from Italy, Egypt, Tunis, 

 England, France, northern Europe, Japan, India, the Philippines, 

 and possibly the United States (North Dakota, Iowa). 



Morphology and Staining. The organism as it occurs in tissues 

 does not show budding forms ordinarily, but reproduces by a 

 series of sporulations. In iriounts prepared from the tissues it 

 has a double refractive contour, which makes it stand out dis- 

 tinctly from the remainder, even when unstained. It is usually 

 spherical or ovoid, 3 to 4 ,u in diameter. The cell contents may be 

 homogeneous or granular. In culture-media the organism consists 

 of hyphal and spherical forms. Cells 

 with buds may be found, identifying 

 the organism definitely with the Blas- 

 tomycetes. Cells containing granules, 

 and resembling closely the resting cells 

 of the yeasts, are common. It has 

 not been conclusively shown that true 

 sporulation takes place in culture- 

 media. The organism stains readily Fig. 168. Blastomyces far- 



with aqueous anilin dyes and is gram- ; cells from culture- 



(adapted from Toko- 



positive. The latter method of stain- s hi g e). 



ing is useful in demonstrating the or- 



ganism in pus or tissues. The alcohol must not remain too long 



in contact with the organism or it will lose color. 



Isolation and Culture. The R. fardminosus is isolated upon 

 culture-media with considerable difficulty. Several investigators, 

 particularly those holding to the protozoan nature of the organism, 

 deny that it has been accomplished. In view of the success which 

 has attended the cultivation of an essentially similar organism 

 in man, there seems no good reason to deny that Tokoshige and 

 others have succeeded in securing it in pure cultures. A slightly 

 acid medium is said to be more favorable than one which is alkaline. 

 Growth is very slow in any event. 



Bouillon finally shows a white, flocculent deposit. Upon 

 the surface of agar, gray-white granular colonies make their ap- 



