82 



MOLDS BELONGING TO THE PHYCOMYCETES 



rales are found to form definite sporangia with numerous sporangio- 

 spores at the ends of the sporangiophores, and conidia (or spo- 

 rangiola) on lateral branches. Other species which resemble the 



Mucorales in all other respects (and are 

 therefore retained in that order) reproduce 

 only by conidia. 



Entomophthorales. Members of this 

 order will not be encountered in bacterio- 

 logical work. As their name implies, they 

 are mostly parasitic on insects. One of 

 the best known, Empusa Muscae, causes a 

 disease of the common house fly. The my- 

 celium penetrates the body tissues and 

 forms sporophores on the surface (Fig. 32) . 

 The flies are killed by the fungus, and are 

 frequently found in the fall on walls or 

 windows covered with a whitish powder- 

 like coating. When mature, the conidia 

 are projected forcibly for a distance of several millimeters, and form a 

 white deposit about the dead fly, especially discernible upon window 

 panes (Fig. 33). 



Mucorales. There are three extensive monographs on the Muco- 

 rales and a very excellent treatise on the Phycomycetes as a whole.^ 



Fig. 32. Stained section 

 through the body wall of 

 a house fly infected with 

 Empitsa Muscae, showing 

 the development of con- 

 idiophores and conidia. 

 Note the multinucleate 

 character of the my- 

 celium. 



Fig. 33. A fly dead of Emrmsa Muscae infection. The white powder surround- 

 ing the fly is composed of conidia which have been discharged for some distance. 



Lendner^ divides the order into two suborders and eight families, 

 Naumov " into three suborders and eight families, and Zycha ' into 

 three suborders and six families. The limits of genera as well as of 



