50 MORPHOLOGY 



bacteriological stains (anilin dyes) do not stain spores. It 

 requires special methods to stain these highly ref ractile bodies. 

 Arthrospores. In certain vegetative bacterial cells, Clado- 

 thrix, Thiothrix, and perhaps a few micrococci which grow in a 

 filamentous form, it is claimed by some writers (Hueppe, et al.) 

 that some of the cells increase in size, become refractile, but 

 stain easily and develop a higher power of resistance than the 

 other members of the same group of individuals. They de- 

 tach themselves from the thread and swim about in the me- 

 dium surrounding them. These cells are called arthros pores. 1 

 It' is claimed that when reproduction takes place these cells 

 are the only ones concerned in the process. There is no new 

 formation within the protoplasm of the vegetative cell, as in 

 most spore-forming bacteria, but the whole of the protoplasm 

 of the cell enters into the formation of the body known as the 

 arthrospore. They do not possess any such increased powers 

 of resistance as do endospores. The majority of bacteriolo- 

 gists at the present do not recognize any such body as the 

 arthrospore (see Fig. 38). 



Reproduction among the Trichobacteria (Higher Bacteria) 



The higher bacteria are usually filamentous forms, and in a 

 large number of species possess sheaths. The filaments are made 

 up of individuals which are separate but connected terminally 

 with each other. One end of the filament is usually attached 

 to some object. After reaching a certain length the cells on 



1 Not used in the sense proposed by De Bary. 



