THE PARASITE OF SPOROTRICHOSIS 673 



of agar deposited on the slides by lightly touching it with a platinum needle 

 charged with pus. Small colonies soon appear on the slides if kept at the 

 ordinary temperature and they can be examined directly. 



The colonies consist of a mycelium and spores. 



The spreading mycelium is formed of long, delicate, colourless, septate 

 and branched filaments measuring about 2/x across. 



The spores or conidia are brown, oval or fusiform (3-6ft x 2 4/x) and though 

 occasionally arranged round the mycelial filaments, are more frequently 

 collected in clusters of 3 to 30 on the end of the filaments. 



In some sugar media no mycelium is seen, and the parasite then assumes 

 the yeast-like appearance which it has in the tissues. 



Staining reactions. The Sporotrichum stains easily with the aniline dyes 

 and particularly well with Unna's blue : haematoxylin is useful for staining 

 the spores. The parasite stains irregularly with Gram's stain, portions only of 

 the mycelium retaining the violet. The spores are, to some extent, acid-fast. 



(/3) Cultures. The Sporotrichum grows only in presence of air : on ordinary 

 media the growth is poor but on media containing sugar or glycerin it grows 

 luxuriantly. Sabouraud's agar is the most suitable medium : 



Water, - 1000 c.c. 



Peptone, - 10 grams. 



Crude glucose, - 40 



Agar, 18 



The organism grows at any temperatures between 12-39 CL but best 

 between 20 and 30 C. 



Sabouraud's agar. Sow 1 c.c. of pus on the surface of the medium and 

 leave at the temperature of the laboratory. De Beurmann and Gougerot 

 adopt this method of cultivation as a means of diagnosis. 



In from 4r-10 days a characteristic growth develops : at first a dull spot, 

 about the sixth day it becomes whitish streaked with blue, dry and convex ; 

 later the colony folds on itself like the convolutions of the brain and is sur- 

 rounded by a shiny areola ; after about 12 days to 3 weeks the colour changes 

 to brown and then to brownish-black, while the areola remains white and 

 becomes covered with a white dust. 



If at the same time as the surface of the medium is sown the dry wall of 

 the tube be also sown the organism grows on the glass, and can be examined 

 in that situation. 



Glucose-broth. Growth takes the form of white pellicles which are formed 

 one after another each in turn sinking to the bottom ; occasionally in old 

 cultures the pellicle is brown. The broth remains clear. 



Glycerin-carrot. Glycerin-beetroot. White colonies appear in about 3 

 days ; these rapidly coalesce to form a layer which is at first white and later 

 brown or even black, the growth at the same time becoming folded and 

 looking as though dusted with powder. 



2. Experimental inoculation. 



Eats and white mice are particularly susceptible. Sub-cutaneous inocula- 

 tion is followed by the formation of an abscess at the site of inoculation, 

 which subsequently softens and ulcerates ; then a number of sub-cutaneous 

 " gummata " appear, osteo-arthritis develops in several joints and occasionally 

 abscesses form in the lungs, liver and spleen. 



Intra-peritoneal inoculation leads to an acute miliary pseudo-tuberculosis 

 or to lesions of sub-acute pseudo-tuberculosis. In male rats a double orchitis 

 is a common complication (de Beurmann, Gougerot and Vaucher). 



Monkeys are also susceptible. Rabbits, newly-born guinea pigs, dogs and 



