28 



BACTERIOLOGY. 



Fig. 13. Gonidia and Arthrospores. 



A-E. Crenothrix, the ends of the filaments are the places where 

 spores are formed the sporangia. A and D, macrogonidia : the 

 segments of the filament are undivided or broken up only into 

 quite large pieces (A, a). B, C, E, microgonidia formed by re- 

 peated division and subdivision of the segments : after expul- 

 sion from the filament zoogloea forms (C, c and E, c) may occur. 

 These microgonidia, and in Beggiatoa the macrogonidia also, 

 may at times develop flagella and become swarm spores. K, the 

 formation of arthrospores in rods from direct observation (Hu- 

 the previously homogeneous protoplasm becomes gran- 



ular (a), contracts (b), divides (c, d, e t ) into two highly refractive 

 arthrospores, each of which is surrounded by a membrane (e). 

 F, arthrospores of B. Zofifii, after Kurth. G, Leuconostoc, after 

 van Tieghem. H and 7, comma bacilli, after Hueppe ; these 

 form (J. d, e} zooglceae composed of coccus-like arthrospores. 



with the polar granules produced by plasmol- 

 ysis. It must be remembered also that the 

 gonidia of the filamentous bacteria may often 

 form zoogloeal masses of coccus-like forms. 

 In such gonidia flagella have been sometimes 

 observed, showing an affinity to real swarm- 

 spores. Coppen Jones T has recently made it 



1 Centralbl. f. Bakt. xvii, 1895, I - 



