ORGANS OF REPEODrCTION. 



385 



may either occur in the same conceptacles -with the sporangia, 

 or in different ones, and then either on the same or on distinct 

 individuals. When conceptacles of both kinds occur on the same 



Fig. 840. 



Fig. 841. 



Fig. 842. 



Fig. 840. Section of a concertacle of Fucus canalicidatiis, containing spo- 

 rangia, sp, antheridia, and paraphyses, par. s. Opening by which the 



spores escape. After Henfrey. Fig. 841. Antheridium of Fucus ser- 



ratiis, with two ciliated a7itherozoids, phytozoa, or spermatozoids in its 

 interior. Fig.Si2. Filamentous cellular bodies, from the inner sur- 

 face of a conceptacle, bearing antheridia, a, a, a. p. Paraphyses or 

 abortive filaments. 



plant, this is termed mwicecious ; if on different plants, the plants 

 are dioecious. By some algologists, the plants are termed herma- 

 phrodite when both antheridia and sporangia occur in the same 

 conceptacle. The delicate jointed filaments which in all cases 

 surround the sporangia, but upon which no antheridia are found, 

 are termed paraphyses (fig. 842, p). The antheridium contains 

 a number oi spermatozoids, anthcrozoids, or phytozoa, of various 

 shapes, each of which is furnished with two cilise of unequal 

 length {fig. 841). 



Pringsheim has recently proved that the apparent decay of 

 the terminal cells of Sphacelaria is caused by the resolution of 

 their endochrome into antherozoids, which ultimately escape by 

 a long tubular opening which is formed in the walls of these 

 cells. 



