678 



THE PARASITIC MOULDS 



species rather than to M. mucedo. It has been recorded also in association 

 with a Tricophyton parasite in the epidermal scales of the horse (Lucet and 

 Costantin). 



SECTION III. THE GENUS RHIZOMUCOR. 

 Rhizomucor parasiticus. 



This species was found by Lucet and Costantin in the sputum of a woman 

 suffering from a condition resembling tuberculosis. 



In cultures, it gives rise to a mycelium grey at first and later fawn-coloured 

 with erect aerial mucor-hyphae or stolons. The fertile pedicels are branched 

 and form a raceme or, more rarely, a corymb. 



R. parasiticus is pathogenic to man [pulmonary rhizomucor-mycosis], 

 rabbits, guinea-pigs and fowls. 



FIG. 320. Rhizomucor varaidticus. 

 (After Lucet and Costantin.) 



FIG. 321. Rhizopus nigricans. P, pedicel ; C, columella 

 S, sporangium. 



SECTION IV. THE GENUS RHIZOPUS. 

 1. Rhizopus nigricans. 



Syn. Ascophora nigricans. 



R. nigricans is, according to Megnin, a dangerous fungus, being responsible 

 for most of the cases of illness following the consumption of mouldy foods. 

 It does not seem, however, to be pathogenic. 



Morphology. R. nigricans forms blackish spots which consist of a very 

 freely-growing, blackish-brown, highly-branched mycelium with internodes 

 carrying spore-bearing hyphae terminating in globular sporangia. When 

 the sporangia (fig. 321 S.) burst, the envelope becomes inverted and the ovoid 

 or irregularly rounded spores contained within it are set free. 



2. Rhizopus niger seems to be merely a variety of R. nigricans. It has 

 been recorded by Ciaglinski and Hewelke in certain cases of black tongue 

 (p. 706). 



3. Rhizopus cohni was found in the rabbit by Lichtheim. Its characteristic 

 feature is the colour of the mycelium, which is at first white but later assumes 

 a mouse-grey colour. It is pathogenic to rabbits. 



4. Rhizopus equini was found in the horse by Lucet and Costantin. It is 

 pathogenic to rabbits. 



