1004 THE HIGHER BACTERIA, MOLDS AND FUNGI 



origin also attack the glabrous skin especially in children. In the 

 epidermis of the diseased scalp they appear as curved branching 

 hyphae made up of elongated elements. The stumps of the diseased 

 hairs are covered with a mosaic of small round spores of uniform 

 diameter (about 2 microns) which completely envelops the hair. 

 If the hair is crushed, mycelial threads are also seen which grow 

 along the medulla. From these central filaments branches project 

 out through the cortex and give rise to the sheath of spores. 



Cultures. These parasites are easily cultivated. They grow 

 rapidly on agar producing large flat colonies which from the first 

 are covered with a duvet of aerial hyphaB. At the center is a raised 

 papilla and from this folds in the membrane radiate out. The color 

 of the duvet varies from snow-white to deep buff and of the mem- 



Fio. 116. MICROSPORON LANOSUM (Six Weeks Culture on Sabouraud's Test Medium 

 \ Natural Size. Hopkins). 



brane from buff to brilliant orange or even a russet brown. The 

 pigment, which is well developed only on glucose-containing media, 

 is diffusable. Gelatin is very slowly liquefied. 



Morphology. In young cultures, long straight coarse trunks 

 radiate out from the center giving off frequent branches which 

 later form an inextricable tangle of threads running in all directions. 

 Some terminal branches bear conidia attached to their sides by a 

 flattened facets (Acladium type). They also form chlamydospores, 

 and fuseaux. 



Sabouraud describes eleven species of microspora which he divides into 

 two groups : one affecting man only and one affecting both animals and man. 



Microsporon Audouini. This is the type species of the former group. 

 In gross appearance the cultures are distinguished by their slower growth, 



