630 LABORATORY HINTS 



Streptothrix madura. 



This fungus produces in Cyprus, India, South America and Egypt 

 the white form of madura disease or mycetoma, which is much more 

 common than the black or red varieties. It does not form yellow or 

 black pigments in cultures, and does not liquefy gelatin. It is not 

 infective for rabbits. The clubs do not stain by Gram. 



Stain with hsematoxylin and acid or carbol thionin. 



THE HYPHOMYCETES. 



The moulds or mycelial fungi are multicellular organisms composed 

 of filaments which interlace, forming a mass of mycelium. 



(1) Mucorinal. 



The end of a filament or hypha swells into a knob around which a 

 spherical seed capsule forms. When ripe, the spores burst the enclos- 

 ing membrane and thus become free. It occurs in any decomposing 

 material and in man ma}- occur in the ear, old abscesses and bron- 

 chiectatic cavities. 



(2) Aspergillinae. 



The heads of the filaments are covered with a number of spore 

 carriers (sterigmata), each sterigmata bears a chain of spores. 



They may invade the lung, blocking up the acini, giving rise to 

 symptoms much like phthisis. 



(3) Penicilliacese. 



The filaments are branched, from these basidia arise the sterigmata 

 from which in turn chains of spores arise. Thev will soon overrun 

 any exposed agar plate. 



Penicillium glaucum is the commonest mould and is seen on moist 

 bread, damp boots, &c., as a bluish-green fur, giving off a musty odour. 

 To mount moulds remove the thin layer of fat that normally covers 

 them, with alcohol and a little ammonia. Then mount in glycerine. 



They can be stained with Loffler's methylene blue, which stains the 

 mycelium and livph^e, the spores remaining unchanged. 

 Another method of showing moulds is to : — 



Stain with aniline gentian violet, five minutes. 

 Pour off, blot, treat with Gram's iodine, two minutes. 

 Treat with aniline oil and iodine until differentiation is com- 

 plete, about fifteen minutes. 

 Treat with xylol and mount in Canada balsam. 



Ringworm. 



This is a kind of mould. It has the power of living on the 

 keratinized products of skin which it breaks up and digests. 



