■0. 



.•-11 of tliG iruicrospor. - colls of the soin.-is. 



Mono of the latter tlien Ccin bo clGVulopcd fron c. liu -x 

 the capsule dorsal to the marginal coll as Bfisgon (*'0) 

 thought possible. In stigittal section (Fi£^. ''") !'■ nip.y 

 "be seen tliat , as suggested above, pericline.l v.'alle, are 

 foiTied in the microspor: .ngiuni mother cells cura ilie inner 

 indusial cells about opposite those in the macrosporejigiiim 

 mother cells, as thej' keep pace with these in radial rrovAAi. 



By the time tliat the \vh0l9 number of macrosporangiujn 

 mother cells has "been fonned in the sorus, th.e soral ca- 

 nal has ben' a\Yay from the median v/all belov/ and slir;htl:; 

 tov/tird the medi;.m v/all at the ventral end (Fig, O-^!-). It 

 is sometimes the case as Bfisgen has pointed out th.at the 

 sporangial cells may grov; over into contact v/ith the inner 

 layer of the indusium, but there is certainly no .q;rov.nng 

 together c'i'ter the first separation imO. the piienomcnom 

 has no significLince. Soon after the soral cejial has taken 

 .ills curved form the cells of sections V ;jia VI come 

 into contact and tlius close the outer end of tlie canal. 

 Tliese soon fuso together firmly but tlie line 01 jiiriction 

 :-emi.ins visible for a lon^ time* (pig* <-^0« 



Wliile the five divisions of the basiscopic marginal 

 c:^ll have increased in numl)crs by radi.il grov.^h they hav 

 also been developing in otlier directions. Tlie soral cav- 

 ity or canal is at first considerabl:' larr-'r at tl .1 



