FLORIDE^. 



81 



1867) differs in the essential points from that of all other 

 plants, and approaches most nearly to the sexual reproduction 

 of the Bangioidece. The sexual cells are developed from the 

 terminal cells (never nodal cells) of the branched cell-filaments, 

 which constitute the thallus. The mother-cells of the spermatia 

 (xpermatangia) are generally arranged in a group, in the so-called 

 antheridia (Figs. 74, 77 A, a). On becoming ripe the membrane 

 of the spermatangium ruptures and the spermatia emerge as 

 spherical or ovoid, naked (a little later they may possess a cell- 

 wall) masses of protoplasm which are not endowed with the power 

 of motion, and hence are carried passively by the current of the 



i 



FIG. 77. A Lejolisia mediterranea : r haptera ; s longitudinal section t^rou'jrh a cystocnrp ; 

 *p the empty space left by the liberated spore (0- B-E Nemalion multifidum: a antheridia; 

 b procarpium with trichogyne, to which two spermsitia are adhering. 



water in which they may happen to be, to the female cell. This 

 latter is analogous with the oogonium of the Green Alga?. The 

 female reproductive organ is termed the procarpium, and consists 

 of two parts, a lower swollen portion the carpogonium (Fig. 77 6 

 in A and B) which contains the cell-nucleus, and an upper 

 filamentous prolongation the trichoyyne (Fig. 77 B) which is 

 homologous with the colourless receptive spot of 'the oosphere of 

 the Green Algae, and the Porphyracecv. In the sexual reproduc- 

 tion of the majority of the Floridere, a very important part is 

 played by certain special cells, rich in cell -contents the auxiliary 



