XEMALIOX 



217 



i 



trichogyne then withers above the fertilized female cell. The 



o/ 



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- 

 ochccte (Sec. 222). Its peculiar 

 form, with a receptive organ, the 

 trichogyne, is undoubtedly asso- 

 ciated with the nonmotile habits 

 of the sperms. The red algae 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, 7>). The terminal cells 

 of the fertile filaments become 

 spores, termed carpospores, which 

 develop new Ncmalion plants. 

 The cystocarp is clearly a new 

 type of fructification in the algae. 

 It -is a structure which begins 

 with the fertilization of the carpo- 



FIG. 203. Nemalion multifidum 



A, anthenclia, consisting of groups of 



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



tion Of carpospores, and thus f ngle sperm: the vegetative 



branch at the right illustrates the 



stands as a phase in the life his- 



tory inserted between two gener- 

 ations of the sexual plants. 



244. Batrachospermum. 



BqtracJiospermum is one of the 



few fresh-water forms of the red 



algae, and is also an exceptional 



_type for its color, which is 



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 ; ict, withered trichogyne 



