NEMALION 



217 



trichogyne then withers above the fertilized female cell. The 

 female cell is called the carpogonium, but it corresponds ex- 

 actly to an oogonium, and indeed resembles very closely the 

 oogonium of some species of Cole- 

 ochcete (Sec. 222). Its peculiar 

 form, with a receptive organ, the 

 trichogyne, is undoubtedly asso- 

 ciated with the nonmotile habits 

 of the sperms. The red algse are 

 clearly heterogamous in their 

 methods of sexual reproduction. 

 The female cell, or carpogoni- 

 um, after fertilization, gives rise 

 to a dense cluster of short fila- 

 ments, called fertile filaments, 

 which all together form a globular 

 fructification called the cystocarp 

 (Fig. 203,D). The terminal cells 

 of the fertile filaments become 

 spores, termed carpospores, which 

 develop new Nemalion plants. 

 The cystocarp is clearly a new 

 type of fructification in the algse. 



It is a structure which begins 



FIG. 203. Nemahon multifiaum 



with the fertilization of the carpo- 



A, anthendia, consisting of groups of 



gonium and ends with the forma- small cells, each of which develops 



a single sperm; the vegetative 

 branch at the right illustrates the 

 method of terminal growth and the 

 protoplasmic connections between 

 the cells. B, the female cell, or car- 

 pogonium, c, with its trichogyne, 

 t, to which are attached three 

 sperms. C, early stage in the de- 

 velopment of the cystocarp; the 

 trichogyne above has begun to 

 wither. D, mature cystocarp com- 

 posed of fertile filaments which 

 develop the carpospores cs termi- 

 nally ; wt, withered trichogyne 



Hrm of rarrmcmnrp<; and 



carpospo es, ano 

 stands as a phase in the life his- 

 tory inserted between two gener- 

 ations of the sexual plants. 



244. Batrachospermum. 

 Batrachospermum is one of the 

 few fresh-water forms of the red 

 algae, and is also an exceptional 

 type for its color, which is 



