TBB CRTFTOOAMIA OR FLOWEBLESS PLANTS. 



129 



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

 gones, or perish. 



634. Altehnate generation is a phenomenon distinctly traced in many of the 

 cryptogams. Thus the mosses, In germinating, first produce long, greenish fila- 

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

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

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

 the ground. Secondly, upon this prothaUus 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 op propagation occur in these plants, as, for example, by 

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



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

 rating from the parent and growing up independent plants. 



053 K» 554 655 SS6 557 



662, Zoospore of one of the Confervaa (Ohaetophora). 65S, PhytozoSn of Chara. 554, Anthe- 

 rldlam of Fncus containing two phytozoa. 555, ZoiispoTe of Conferva with a toft of cUiae. 656, 

 Another species with but two cUiie. 597 Zoospore of Yanoheiia with cilia all around. 



