REVOLVING PLANTS. 55 



break up into a number of antherozoids, as they are 

 now named. These are free and rapidly swimming 

 animal-like bodies, and assembling round the glo- 

 bular gynogoinidia, or germ cells, penetrate the soft 

 gelatinous envelope, and coalesce or are absorbed in 

 them. Thus is formed the winter cell, or egg, which 

 sinking to the bottom of the water, and remaining 

 in this condition during its hibernation, is destined 

 to become the progenitor of another generation. In 

 the spring this egg or spore becomes swollen, breaks, 

 and the contents, consisting of small cells, are pro- 

 jected into the water. Here they soon begin a 

 geometrical method of propagation dividing first 

 into two, then four, eight, and sixteen combined 

 bright-green cells, each with its two filaments of 

 active cilia. 80 is formed the new plant, destined 

 to repeat in its own history all the interesting 

 phenomena of its ancestors, as already described. 



There is yet another phase in the history of this 

 interesting organism. At certain stages some cells 

 lose their vegetable character altogether, and become 

 animals, closely resembling dmcebce a little bit of 

 formless protoplasm, moving hither and thither by 

 throwing out prolongations, or limb-like projec- 



