Mucor Corymbifer, Lichtheim. 



Origin. — Is of rare occiirrence, and was found as a con- 

 tamination on bread- gelatin plates and on white bread 

 which was kept at the body temperature. It has been 

 found in the ear-passages of man. It is probable that this 

 same species has been found in a case of generalized 

 mycosis. 



Color. — The mycelium, spores and sporangia are color- 

 less. 



Mycelium. — Loose, wavy, branching, slender mycelial 

 threads which form a white cotton-like mass an inch or 

 more in height. 



Fruit-organs. — The fruithyphae branch forming clusters 

 or corymbs which terminate in spherical or pear-shaped 

 sporangia. Within these are the colorless, oval or elongated 

 spores, which are about 3 /* long and 2 ij. wide. 



Growth. — Rapid and extensive. 



Bread-flasks — In the incubator it forms a white, elevated, cotton- 

 like growth which soon fills the flask. On potato a similar cotton-like, 

 tall growth develops. 



Temperature. — Grows slowly at the ordinary tempera- 

 ture; best at 37°. 



Pathogenesis. — Intravenous injection of the spores into 



rabbits produces death in 3 to 4 days. The kidneys, 



mesenteric glands and Peyer's patches contain mycelial 



masses. The Peyer's patches are swollen and ulcerated. 



Intraperitoneal injections produce the same results, Dogs 



are immune. 



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