358 



THE IRON BACTERIA. 



If we disregard the exceptions just named, wherein the ger- 

 mination of the cocci proceeds within the parent thread, and so 

 causes it to present a branched appearance, it may be said that the 

 genus Crenothrix appears only in the form of single, unbranched, 

 filamentous chains of cells. This characteristic suffices to dis- 



FIG. 67. Cladothrix dichotoma. FIG. 68. Diagram of the false branching of 



Portion of a thread with several 

 branching forks. Stained with 

 fuchsine solution, and thus re- 

 vealing the articulation into 

 long rods. Magn. 540. (After 

 Zopf.) 



tinguish this genus from that bearing the name of Cladothrix, the 

 best-known species of which is Cladothrix dichotoma. As this 

 name implies, we have here to do with a forked thread, such as is 

 shown in Fig. 67. This false branching is produced in the follow- 

 ing manner : One of the rod-shaped joints of the thread turns 

 aside, and, growing beyond its next higher neighbouring cell, 

 repeatedly subdivides and forms a new thread, on which a similar 



