STUDY AND IDENTIFICATION OF MOULDS 



i. Mucor mucedo and 2. Mucor corymbifer. These moulds develop especially in 

 external cavities as nasopharynx and external ear. 



Pulmonary and generalized infections have also been reported. The pathogenic 

 species have smaller spores and grow best at 37C. The thick, coarse, cotton-like 

 mould seen on horse manure is a Mucor. The sporangium, the organ of fructifica- 

 tion, contains the spores within its interior. The M. mucedo has thick silver-gray 

 mycelium, with large sporangia, 150/1 in diameter, containing oval spores, 5 X QM- 

 The M . corymbifer, which has been reported from a generalized infection, considered 

 as typhoid, shows a snow-white mycelium. The sporangia are 20 to 40ju and the 

 spore about 3/1 in diameter. 



Rhizomucor parasiticus has been reported from the sputum of a 

 woman with a condition resembling phthisis. 



Rhizopus niger has a columella which becomes distorted into a mushroom shape 

 after the spores have been discharged from the sporangium. This mould has been 

 considered as the cause of a mycosis of the tongue. 



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FIG. 40: Yeast cells. Saccharomyces cerevisice. (Coplin.) 



Ascomycetes. In this order are included many of the parasitic 

 moulds. The most distinctive characteristic is the formation of asco- 

 spores in an ascus (little sac). 



It is an enlargec! extremity of a hyphal branch in which a definite number of spores, 

 usually eight, is formed. The ascus usually ruptures at its tip. Other members of 

 the order are formed from hyphae by the separation of cells in succession from the 

 free cells. The mycelium is septate. 



The order is divided into those with naked asci (Gymnoascees) and 

 those having a perithecium or investing layer about the ascus (Car- 

 poascees). 



