THE NATURE OF BACTERIA. 23 



classes, including such forms as molds, mushrooms^ etc. We 

 are only incidentally concerned with them in this work, al- 

 though many are of great importance in agriculture. They 

 are generally characterized by the development of long slen- 

 der threads (inycdiuiti), which grow like delicate roots through 



FIG. i. 



FIG. 2. 



One of the higher Fungi, the common bread mould, Penicilliutu glaucunt. a, the whole plant; 

 b, one of the spore-bearing branches more highly magnified. 



the substance of the material upon which they are nourished 

 (Fig. i). These threads make it possible for them to force 

 their way into hard substances, like wood, 

 and effect their decomposition. 



2. Saccharomycetes. (Budding fungi. 

 Yeasts. ) These immensely important 

 plants are wholly microscopic. They 

 consist of simple oval or spherical cells, 

 usually separate from each other but 

 sometimes adhering in irregular masses Yeast, showing method of bud - 

 (Fig. 2). Their distinctive character is in 



their method of reproduction, which is as follows : From the 

 sides of the cells small buds arise which increase in size by 

 growth until they a're about as large as the original, when they 

 may separate as distinct cells. This method of multiplication 



