lit TIIK NATUBW AND WOltli OF I' LA NTS 



fusG with the foiriiihi gamotcH, as in tlxs fern, and iJio 

 cell forniod gennin.'iioa willioiit leaving il,H jjlacu; as 

 in tlio fern, but Uw. stnuiiun! of Uio indiviiliial 

 formed is very much dirr(!r(3nt. 'I'lio wocond \rr,\\i'.rd- 

 tion conwists of a Hlendcir brownlHli or greenish aU'.in, 

 beariii^f a larfi,(! capsulo. 'I'liiw (!a|)Nid(! i,s coiiipoHC!'! 

 of tissue wliich coniaiiiH chloroiiliyl, is furnlMlKid 

 with a hood or oilier a|)[)cnd;i4^(:H, and contains a 

 flask or sac, tlu; coni('nl-.s of wliicli develop into 

 spores. Till) .spoi'tj.s gonninatc; juid form the ]e;i,fy 

 stemmed planl-H cxainirKid at firwl,, and tlio e;i|)Hulo 

 and il.H ntallc are thus the H|)oropliyl,(! of tlx; rnoHH. 

 It is seen to ho !i.h](! to form hohk! of its food by 

 means of its chlorofthyl, but it is d(^p<nidenl, upon 

 the gametophyto for itn supply of w.dvr ;i,nd mincira,! 

 salts, and is sometimes waid to bo parasitic upon it. 



199. Occurrence of generations. — This alterna- 

 tion of the two geiHjralion.s of a spee,i(!H is not inva- 

 riable. It was found that by ve^^etaiivt! ineLhodH 

 of reproduction (§ ISO) the culting nsproduefis its 

 own generation in all tlu; (ixperirrHjniH tried. Theni 

 are some inwianfiiiH, however, when; the euttiiif^ of a 

 sporophyte will produex! a ganuH-oftliyl.e, ;ind nir.f, 

 versa. Then, af^ain, the uporciH developed hy the 



