BOTANY 



cells of which have peculiarly constructed walls; the wall run.-iM- of two parts 

 separated by an oblique annular split at the middle p.irt of the cell. On cell 

 division a new portion, H-sliaped in longitudinal section, is intercalated. Tin 

 characteristics of the group are seen in the yellowish-green, oil-forming chloro- 

 plasts, and the formation of zoospores with cilia of unequal lengths in many 

 Confervae the zoospores lum- only a single cilium). In addition to zoospores thick - 



walled aplanospores arise by 

 the separation by the cells 

 "I' the filament. 



With some reservation 

 OI.TMANNS also places here 

 ll<il i- ijil lii-i>i ij rii /mint ti, IL (Fig. 

 281). which was formerly in- 

 cluded in the Siphoneac. 

 Tliis Alga grows on damp 



Kii;. -Jsn. .-fii,ij,',-i-n lii-nilii/i-hif. 1, Filament : -'. '. formation 

 of transverse wall (</) in cell division; i>, formation <>t" 

 aplann.sixirfs by lireakinx down of tin- fllainent ; 1<>. 

 Xoos] HUTS with cilia of unequal length. (After CAY 

 (/. .'), lion LIN (.'. :.'). l.i TIIF.R (/"). From OI,IMAS\>' 

 Algue.) 



Pitt -Si. I. /'. 



/at H ni. .'., The \v 

 /.', S\varni-s|Kni-. 

 /: .MO.) 



M 



li<ili> plant : 

 (.1 x 28: 



clayey soil, where it forms groups of green, balloon-shaped vesicles about '2 nun. 

 in breadth. These are attached to the soil by branched colourless rhixoids. 

 The whole plant corresponds to a single multinucleate cell : its protoplasm 

 contains numerous green chloroplasts. The zoospores, produced in large number> 

 by the division up of the contents, escape by an opening at the summit, ivu'h 

 has a single cilium and contains two chloroplasts. After swarming the S|H,I, 

 surrounds itself with a wall and grows into one of the balloon-shaped plants (*). 



In some genera, gametes resembling the zoosp<nvs but conjugating in pair* 

 have been observed. 



