254 



PLANT STUDIES 



The other group, represented by Funis (Fig. 221), pro- 

 duces no asexual spores, but is heterogamous. A single 

 oogonium usually forms eight eggs (Fig. 221, vl), which are 

 discharged ami float freely in the water (Fig. 221, E). The 

 antheridia (Fig. 221, (') produce nuiucrous minute laterally 

 biciliate sperms, which are discharged (Fig. 221, (i), swim 

 in great numbers about the large eggs (Fig. 221, F, //), 

 and finally one fuses with an egg, and an oospore is formed. 

 As the sperms swarm very actively aljout the egg and im- 

 pinge against it they often set it rotating. Both antheridia 

 and oogonia are formed in cavities of the thallus. 



4. Ehodopiiyce.'e {Red Algw) 



172. General characters. — On account of their red colora- 

 tion those forms are often called Floriili'w. They are mostly 



marine forms, and are 



anchored by holdfasts 

 of various kinds. They 

 belong to the deepest 

 waters in which Alga; 

 grow, and it is jjrDljable 

 that the red coloring 

 matter which character- 

 izes them is associated 

 with the dejith at which 

 they live. The Eed 

 Alga? are also a high- 

 ly specialized line, and 

 will be mentioned very 

 briefly. 



173. The plant body. 

 — The lied Alga-, m 

 general, are more deli- 

 cate than the Ih'owii 

 Alg:T3, or kel])s, their graceful forms, delicate texture, and 

 brightly tinted bodies (shades of red, violet, dark pui-ple. 



Fifi. 2W. A red ali; 

 Itraiirhiiio; liiibit, 



AftCT SCIIENCK. 



iiid ■■fruit b.Hlk-s,"— 



