194 BACTERIOLOGY 



and Mncor rhizopodiformis are found upon food-stuffs, par- 

 ticularly bread. They possess a branching mycelium, with 

 spore-bearers which resemble flexible tubes, are unseg- 

 mented, and stand up vertically from the mycelium. At 

 the upper ends of these are the swollen sporangia, by 

 bursting of which the spores are set free. In addition 

 to this process, a kind of conjugation also takes place, in 

 which two cells (zygospores), developed from the mycelium, 

 coalesce with one another and form spores. 



The Mucor mucedo is one of the commonest moulds, and 

 is frequently found in animal excreta, especially in horse- 

 droppings. It grows on acid media, and is not pathogenic. 

 A dense fur with black fructifications as large as poppy- 

 seeds appears on the gelatine plate. 



The Mucor rhizopodiformis was described by Lichtheim. 

 It grows very luxuriantly on bread gelatine, which it lique- 

 fies. The fur is white and bears black fructification heads. 

 The culture on brea'd is distinguished by the development 

 of an aromatic odour. 



Mucor corymbifer was likewise described by Lichtheim. 

 It forms a dense snow-white fur upon bread, resembling 

 teased-out cotton-wool. 



The Mucor ramosus, described by Lindt, grows very well 

 upon agar made with bread infusion, and upon potato. 

 The fur is at first white, but soon assumes a greyish-brown 

 tint. 



Both Mucor rhizopodiforinis and Mucor corymbifer are 

 pathogenic. Intravenous injection of fluid containing their 

 spores causes a fatal disease in rabbits, in which the organs 

 are always attacked in the following order : viz. kidneys, 

 intestine, mesenteric glands, spleen. Mucor ramosus acts 

 quickest, an acute hsemorrhagic disorder being originated 

 by its injection. 



The Aspergillus fumigatus and Aspergillus flavescens in 



