Bacillaria.] the infusoria. 217 



demonstrated by artificial means. At one time it was 

 supposed these animalcules had no mouth, but were 

 nourished by absorption. The self-division is always 

 longitudinal and dorsal, so that the surfaces which hano- 

 together are those of the sides. A small deflection 

 and locomotion of the chains is observable in the first 

 water species, but is more remarkable in the marine 

 varieties of B. paradoxa, which, when separated, move 

 quickly, like Navicula. The name Bacillaria was first given 

 to them by G. Malin, and from botanists take the names 

 of Diatoma, Conferva, and Oscillatoria. They form part 

 of the genus Vibrio of Miiller." 



278. Bacillaria joara^oa^a {Vibrio p axil lifer, M.) The 

 paradoxical Bacillaria has a straight slender striated lorica, 

 often fifteen times longer than it is broad. Nine striae 

 occur in every 1- 100th of a line. They are of a yellow- 

 ochre colour, and their locomotion is distinct. In con- 

 sequence of incomplete self- division they adhere side by 

 side, and the band-like clusters thus formed are either 

 straight, wavy, or zig-zag, according as they slide one 

 upon another. In the engraving, group 167 is a polypi-like 

 cluster, and fig. 166 a front and side view of a single speci- 

 men. Found upon sea-weed. Length l-1150th to l-240th. 



279. Bacillaria vulgaris. The common Bacillaria, or 

 the Diatoma flocculosum of botanists, has a straight lorica, 

 three or four times longer than it is broad. It has thirteen 

 transverse striae in every 1-lOOth of a line of its length. 

 Fig. 168 is the dorsal view of part of a group of four 

 specimens ; viewed sideways, they resemble a spindle. 

 Found both in fresh and salt water : in the Rhone, it 

 covers over Conferva glomerata, in the form of a thick 



