88 MORPHOLOGY OF THE BACTERIA. 



from 2 to 6 /x in length, and about 2 //, in 

 thickness. The single rods and short chains 

 exhibit active movements. Upon the surface of 

 a culture-medium they grow into long motion- 

 less leptothrix filaments, and rapidly develop 

 spores. These are oval, highly refractive bodies, 

 of 1 to 2 p in length, and from .6 to 1 //, in thick- 

 ness. (See Plate III.) 



B. amylobacter, Van Tieghem (Amylobacter, Uro- 

 cephalwn and Clostridium Trecul). 



B. occurring, like the preceding, under various 

 forms, in pointed cylindrical filaments of 6.6 to 

 26 jj, in length and 1.1 /A in thickness, or in form of 

 tadpole, with a spore in the terminal swelling, or of a 

 spindle, with a spore in the middle. In fact, it does 

 not differ from B. subtilis, except by the appearance 

 of starch in its protoplasm at the end of the period 

 of multiplication. These B. are sometimes endowed 

 with movement (Ny lander). 



It develops in vegetable tissues, which fall 

 into putrefaction, spontaneously, according to 

 Trecul, or introduced from without by a mech- 

 anism still unknown. This is the essential agent 

 of vegetable putrefaction (Van Tieghem). 



B. ulna, Cohn ( Vibrio bacillus, Ehrb.). 



Filaments articulated, thick, and rigid, formed of 

 one, two to four articles, straight or broken in zigzag; 

 length of an article 10 /i, length of a filament of four 

 articles 42 ^ ; slow movements of rotation and of 

 progression. 



