42 BACTERIA. 



on much the same features, but he also takes into considera- 

 tion some of the physiological and biological characters, the 

 nature of the processes set up by them, the resulting products 

 and the nature of the division. 



VAN TIEGHEM'S CLASSIFICATION. 

 Van Tieghem places all the schizomycetes in a family which 



Photo-micrograph of Bacillus Figuraus Leptothrix and rod forms, x looo. 



he calls bacteria, a family closely related to the nostocaceae 

 apd the oscillaria of the Algae ; he divides them into micro- 

 cocci ; bacteria or short rods ; bacilli or short threads ; 

 longer threads, without any definite sheath, being called 

 leptothrix ; with a sheath, crenothrix ; with a sheath and 

 undergoing division, cladothrix. 



