

siicill fin. ' ■ ' UG the mother coll of all Mie mi\cro- 

 sporMn^in of the sonic, \re may c:dl i' tJie priimcpy nacro- 

 sporcuigiim mother cell. The sister cell of this latter 

 diviclos once more by a trnsver-o imticlino (Fif^s. ■'"'", '^4) 

 and thus five cells are fonned from the "basicopic ins-rginal 

 cell, tv/o on each side of tho primary macrosporangiuin moth- 

 er cell. Of these the one next to the latter on each side 

 (p.mi - sp.m.c. Figs. Hu, f^4) is a primary microsporangirm 

 mother cell, each givin,r; rise to all the microsporangia 

 of tlie sorus on its side of the placenta. Tlie outer coll 

 on each side (i.ind.. Figs. 56, 64) fomis the inner layer 

 of tlie lateral pairt of the indusiujii. Tlieso five cells are 

 at first much alike as they appear in a transverse set ion 

 of the capsule (Fig. Ol), but the contents of the three 

 middle ones soon "become much denser ( Fig. r? ). 



In horizont;.! section it is soon seen tlifet hile tliu 

 outer or indusial cells, of the five, remain in cont;'.ct 

 ■■/itli the cells of section V , the three middle o." spo- 

 rangium mother cells cire separated from those by a narrow 

 slit (s.c. Fig. D7). This is tlie beginning; of the sortil 

 canal tliat we have already noticed in tlic cross section 

 (s.c. Fig. 01 ). Tliis cavity constantl.' increases in si::o 

 by the pushing out of the indusial cells on each side of 

 the sorus and the forcing away thus of the cells of sec- 

 tion V from tiio sportmgivjn mother colls. 



