Staining 



807 



of from three to six or more conidia, which, in the case of the larger 

 cluster, are attached by the smaller end to the slightly expanded 

 extremity of the branch. Similar ovate buds also arise from the 

 sides of the hyphae at shorter or longer intervals. The spores are also 

 doubly contoured and granular, resembling yeast cells. These 

 various features are well shown in the 

 photographs on the accompanying plate. 

 The attachment, by means of the short 

 pedicles of the spores to the threads, is'very 

 easily severed as shown by the difficulty in 

 obtaining stained preparations with the 

 spores in situ. When placed in the 

 hanging drop, the conidia grow out into 

 one or more straight germ tubes which 

 spring from either or both ends or from 

 the side. These embryonal threads 

 again give rise to lateral or terminal 

 buds, which in all particulars resemble 

 the spores and some of which form branch- 

 ing spore-producing threads, so that in the 

 early stages very peculiar-looking bodies 

 are produced. 



In the tissues and in the pus from the 

 lesions of the disease the parasites have 

 quite a different appearance, assuming 

 a short oblong form like a thick short 

 bacillus 3-5 fi in length and 2-3 n broad, 

 basophilic, finely granular and surrounded 

 by a very delicate, colorless membrane, 

 de Beurmann has watched the growth of 

 this degraded form of the parasite into the 

 filamentous and spore-bearing form, in 

 artificial culture. 



Staining. — The micro-organism is much 

 better examined in the fresh and living 

 condition than dried and stained, as it 

 greatly changes in appearance through 

 shrinking. It does stain, however, with 

 the usual dyes, and retains Gram's stain 

 except when the alcohol washing is unduly prolonged. 



Cultivation. Colonies. — Upon agar-agar, at the end of about 

 forty-eight hours, the colonies appear elevated, whitish, with feathery 

 fringes and some filamentous downgrowths into the medium. Upon 

 gelatin the downward growth results iii liquefaction and the grow- 

 ing colonies sink below the surface. 



Agar- Agar. — ^Along the needle track made by a stroke culture, a 

 grayish granular slightly elevated line with feathery edges forms in 



Fig. 330. — Abscesses 

 caused by Sporothrix 

 sch'enckii. Arm of patienl 

 showing ulcers and scars, 

 at a late stage of the lesions 

 (Hektoen and Perkins, in 

 "Jour, of Exper. Med."). 



