THE STORY OF GERM LIFE. 



Fig. 17 shows a group of these Oscillariae, and 

 the similarity of this to some of the thread-like 



bacteria is de- 

 cided. The Os- 

 cillaricz are, how- 

 ever, true plants, 

 and are of a 

 green colour. 

 Bacteria are 

 therefore to-day 

 looked upon as 

 a low type of 

 plant which has 

 no chlorophyll,* 

 but is related to 

 Oscillarice. The 

 absence of the 

 chlorophyll has 

 forced them to 

 adopt new rela- 

 tions to food, 

 and compels 

 them to feed 

 upon complex 

 foods instead of the simple ones, which form the 

 food of gfeen plants. We may have no hesita- 

 tion, then, in calling them plants. It is interest- 

 ing to notice that with this idea their place in the 

 organic world is reduced to a small one systemat- 

 ically. They do not form a class by themselves, 

 but are simply a subclass, or even a family, and 

 a family closely related to several other common 

 plants. But the absence of chlorophyll and the 

 resulting peculiar life has brought aboift a curi- 



FiG. 17. Threads of Oscillaria, the nearest 

 allies of bacteria. 



* Chlorophyll is the green colouring matter of plants. 



