■ 1. 



fOi'i-iuu vur.i Mil 1..1J Uuipuc.^'j i'.; cue i:Ulli.;.n. ...;/ in iuiyoiU 



Tlie semicircular Go^-menU of tlio j.pic;il colla ve diviO. cl 

 'b^r lonjf^i-l/aclinal :in; iclinoG in"! o si/, u Cwion':; ;.nu ai-L ulti- 

 mate marginal coll of the sovcntli grade, Tlio dorsn.l bun- 

 dle of the capsule is fonned entirely from t]ie pluroni^- 

 01 seci'ion I , -he lateral bundles in tliat of 8. ctions 

 III LOid IV ..u,. ,.e ^'l:ict:ntal bundle and brmci: in sec- 

 tion VI . The epidermis is of one layer oi cells and 

 tiie liypodermis of tv/o, botli layei-s of th.e latter consist- 

 inr; of very thick walled cells. The trich-omes of tlie 

 epidevrais and th.e ai canals :inLior ^iie hypoa^.iT.iis a:-o like 

 tiiose of the petiole, except that the latter are sma'ler 

 and more irru^^ular. The sporangi^i o.. viica 'ju/us ■:. e all 

 derived from a basiscopic ultimate marginal cell, which 

 gives rise also to ^ he cellr^ lonning unu inner layer of 

 the lateral portion of th.e indusiujiu The single priiriary 

 macrosporangi^Tii mclJior cell and the tv/o primary micro- 

 sporangium mother cells of each so]n:s are sistev cells, 

 formed by the first divisions of tlio margin^.! cell. Tliey 

 are thus superficial , but not strictly epidoiTaal, in 

 origin. Tiio soral canal arises by a split between the v/all:; 

 of tlio primary sporangium mo'vh.er cells and those of th.c 

 cells of section V , beginning at tlie ventral '^^^ • ' .ce 

 of the capsule and extondin. ; later to the inner onii of 

 he fon'icr. Fron 'lie space so fonned i-: developed the 



