THE CRTPTOGAMIA OE FLOWERLESS PLANTS. 



129 



antheridia (as pollen?) and actively floating until they react the arche- 

 gones, or perish. 



634. Alternate oeneration is a phenomenon distinctly traced in many of. the 

 cryptogams. Thus tlie mosses, in germinating, first produce long, greenish fila- 

 ments quite analogous to the Conferva (frog'a-spawn). From these, at length, buda 

 arise and grow into a true moss. Ferns, also, and Equisetaoese, first from the spore 

 exist in the form of a hverwort — a small green thallus, creeping and rooting along 

 the ground. Secondly, upon this proihalius reproductive organs are developed and 

 an embryo, whence a true fern arises. Thus the plant is transiently, as it were, a 

 liverwort, permanently, a fern. (§21 — 23.) 



635. Other modes of propagation occur in these plants, as, for example, by 

 innovations, sporules, gonidia. These bodies are analogous to bulbs and bulblets 

 in the flowering plants, originating from the nutritive organs, and capable of sepa- 

 rating fi-om the parent and growing up independent plants. / 



852 56S 654 555 556 557 



553, Zoospore of one of the Confervae (Chaetophora). 853, Phytozoon of Chara. 554, Anthe- 

 ridiam of Fucus containing two phytozoa. 555, Zoospore of Oonfervse with a tuft of cilisB. 556, 

 Another species with but two cilise. 5ST Zoiispore of Vauchoila with ciliee all around. 







