Staining 



761 



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 hyphse at shorter or longer intervals. The spores are also 



doubly contoured and granular, resembling very much 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 easUy 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 resembles the spores and 



some of which form branching spore-pro- 



ducing 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 ba- 

 cillus 3-5 fi in length and 2-3 ^ 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 ar- 

 tificial culture. 



Staining. — The micro-organism is much 

 better examined in the fresh and living con- 

 dition 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, 

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

 fringes and some filamentous downgrowths into the medium. 

 Upon gelatin the downward growth results in liquefaction and the 

 growing 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 

 forty-eight hours and in seventy-two hours assumes the form of a 



Fig. 322. — Abscesses 

 caused by sporothrix 

 schenckii. Arm of patient 

 showing ulcers and scars, 

 at a late stage of the lesions 

 (Hektcen and Perkins, in 

 "Jour, of Exper. Med.")- 



at the end of about 



