DUST PLANTS. 



-S3 



Another micro-organism which is seldom absent 

 from house dust, either as the plant cell itself or its 

 spore, is mold. This in our dust garden formed the 

 :olonies with dark centers and a velvety pile. Molds 



Growth of 

 Mold 



FIG. 18. A GROWTH OF MOLD. 

 Mycelium, Hyphae and Spore-cases. (After Jorgensen.) 



consist of vegetative portions which grow out in long 

 threads, and these by budding and branching unite 

 to form a network over the substance they are using 

 as food. Fig. 18. 



From this network or mycelium grow out cells called 

 Jiyhae set apart for special wprk that of bearing the 

 reproductive portion the heads or stalked clubs. 

 Inside these heads or from their outer surface 



