THE RELATIONSHIP OF BACTERIA 121 



do. They are commonly found together with saprogenic 

 bacteria on decaying animal and vegetable material. The 

 fungi cells are granular, nonnucleated, and the protoplasm 

 watery and colorless. They are usually found collected to- 

 gether into filaments called hyphae. Interwoven hyphae 

 are collectively called a mycelium. The fungi, no matter 

 what species, can be separated into two distinct parts, the 

 mycelium or vegetative part, and the fruiting head or spore- 

 bearing, reproductive part. No such separation occurs in 

 the lower bacteria. In the higher bacterial forms, when re- 

 production takes place, all the cells in the filament which 

 are destined to reproduce form gonidia, and the vegetative 

 state for these cells ceases to exist. This is also true in a 

 measure in reproduction among the Myxomycetes, or slime 

 molds. 



The fungi are related to the algae through a common 

 ancestry. There is a group among the algae, or closely 

 related to them, which is called the Phycomycetae, or algo- 

 fungi. Some botanists hold the view, on seemingly a good 

 basis, that the fungi are modified algae which have lost their 

 chlorophyll and acquired saprophytic habits. 



The yeasts or Saccharomycetes are certainly very closely 

 related to the bacteria. They are unicellular plants which do 

 not ordinarily produce filaments and are devoid of chlorophyll. 

 While having many physiological processes in common, they 

 differ from the bacteria in the method of reproduction, the 

 bacteria reproducing by fission and the yeasts by budding. 



