FAMILY BATBACHOSPERME.E. 



337 



Fig. 157. 



inhabitants of Fresh water, and they are chiefly found in that 

 which is pure and gently-flowing. ' ' They are so extremely 

 flexible," says Dr. Hassall, "that they obey the slightest motion of 

 the fluid which surrounds them ; and nothing can surpass the ease 

 and grace of their movements. When removed from the water 

 they lose all form, and appear like pieces of jelly, without trace of 

 organization ; on immersion, however, the branches quickly resume 

 their former disposition." Their colour is for the most part of a 

 brownish-green ; but sometimes they are of a reddish or bluish 



purple. The central 

 axis of each plant is 

 originally composed 

 of a single file of 

 large cylindrical cells 

 laid end to end; but 

 this is subsequently 

 invested by other 

 cells, in the manner 

 to be presently de- 

 scribed. It bears, 

 at pretty regular in- 

 tervals, whorls of 

 short radiating 

 branches, each of 

 them composed of 

 rounded cells, 

 arranged in a bead- 

 like row, and some- 

 times subdividing 

 again into two, or 

 themselves giving off 

 lateral branches. 

 Each of the primary 

 branches originates 

 in a little protube- 

 rance from the primitive cell of the central axis, precisely 

 after the manner of the lateral cells of Conferva glomerata 

 (§ 249) : as this protuberance increases in size, its cavity is 

 cut off by a septum, so as to render it an independent cell ; and 

 by the continual repetition of the process of binary subdivision, 

 this single cell becomes converted into a beaded filament. Certain 

 of these branches, however, instead of radiating from the main 

 axis, grow downwards upon it, so as to form a closely-fitting 

 investment that seems properly to belong to it. Some of the radi- 

 ating branches grow out into long transparent points, like those of 

 Chastophoraceae ; and it does not seem by any means improbable 

 that these, like the ' horns ' of Vaucheria (§ 246), are really An- 

 theridia. For within certain cells of other branches 'resting- 



Batrachospe r nnum moniliforme. 



