762 Sporotrichosis 



band with numerous transverse wrinkles; in a couple of days more 

 " the surface becomes more markedly corrugated and looks like a 

 chain of mountains on a map." About the seventh day, the 

 growth, which has increased in thickness, becomes Ught brownish in 

 color, the margins being smooth and wavy and marked by shallow 

 transverse grooves. Still later the growth becomes dark brown, 

 wrinkled and covered by a delicate fuzz. The agar-agar becomes 

 brown. 



Gelatin. — In gelatin punctures the growth is confined to the upper 

 strata. Lateral branches are sent out from the needle track. A sur- 

 face felt-like mass of mycelial threads forms beneath which the gela- 

 tin liquefies. The surface growth sinks into the liquid medium. 



Blood-serum. — ^The growth is somewhat like that on agar-agar 

 but not so massive. It is apt to be covered by a white down. 



Bouillon. — The growth which is fairly abundant, is in flakes and 

 tufts, shreds and filaments that settle to the bottom or cling to the 

 sides. A white surface film is apt to cover the liquid. No fermenta- 

 tion occurs in sugar bouillon. 



Potato. — 'Upon potato tufts form in twenty-four hours. These 

 have a brownish-gray color and soon become raised, wrinkled, and 

 frosted. The potato is darkened. 



Milk. — The growth is scanty and owing to the opacity of the 

 medium, difficult to see. Litmus milk is not acidified. There is 

 no coagulation. 



Vital Resistance. — The optimum temperature is about 37°C. The 

 organism grows slowly at room temperature but in the end attains 

 pretty much the same magnitude as those kept in the thermostat. 

 The death point is 55°C. for one hour. Hektoen and Perkins found 

 S. schenckii killed in four and one-half minutes at 6o°C. 



Metabolic Products. — The organism produces no curdling or 

 proteolytic ferments for milk or blood-serum. It does, however, 

 liquefy gelatin. It grows aerobically or anaerobically, but under the 

 latter conditions it does not produce acid or ferment sugars, or 

 evolve gas. No indol is formed. It has a remarkable tolerance 

 for acid media. Page, Frothingham and Paige* found that it grew 

 well in media at least six times as acid as those ordinarily employed 

 for bacteria. They also found that the organism does produce acid 

 in media containing dextrose. 



Distribution in Nature.^ — -According to de Beurmann, the sporotri- 

 chum is a widely distributed micro-organism in nature. It has been 

 found on green vegetables, upon bark, thorns, potatoes, various im- 

 plements, in the soil, and in infected insects. 



Pathogenesis. — -The sporotrichum is pathogenic for men, horses, 

 rats, dogs, and white mice. 



It would seem as though the rarity of its occurrence as a patho- 

 genic agent signified that it was by no means easy for it to effect the 

 * "Jour. Med. Research," 1910, xxiii, p. 129. 



