SECT. ii. CONFERVACE&. 209 



end to end. The spores only grow on the filaments 

 that are exposed to the sun and air ; the filaments that 

 are below the water are green and barren. The spores 

 are filled with red matter, grains of starch, and red oil, 

 the outer or cellulose coat being so plaited, that the 

 spore looks like a red star with white, rays. 



When a spore germinates, it produces a minute cell 

 ending in capillary fibres, which increases in length by 

 the continual bisection of its central cells, while the 

 other Confervse grow by the bisection of those that are 

 terminal. During this growth, the red contents of the 

 spore are so changed by a remarkable succession of 

 chemical processes, that the primordial cells in the 

 filament of the young plant are filled with a colourless 

 viscous matter, an aqueous liquid, granules of starch, 

 and chlorophyll. In some of the cells the starch dis- 

 appears, while the green matter and the other materials 

 arrange themselves into a series of rings, alternating 

 with empty spaces or vacuoles. After a time, the green 

 changes to a yellowish red, and then each ring in 

 succession resolves itself into a multitude of minute 

 active particles, which move with incredible velocity in 

 the void spaces of the cell, till at last the whole cell 

 swarms with them. They are analogous to the pollen 

 of flowering plants, and thence are called spermatozoids. 

 Their form is cylindrical, thick, broad, and yellow at 

 one end, sharp at the other, with a colourless beak, and 

 long cilia. The parent cell is at last pierced by their 

 united efforts, and out they rush in great confusion 

 into the water ; some whirl round their centres, others 

 swim in a circle, many describe cycloidal curves by a 

 series of leaps, and a few swim in straight lines. 



During the preceding changes another process is in 

 progress, within what may be called female cells. In 

 these the starch, mixed with green matter and a 



VOL. i. p 



