0. 

 uHi£<;e direcuGcl iov/; w.,... "^ :;iic- — 



cular SG;;ments of Uiis aru aividecl lirot, b^^ I'iv; loru-;!- 

 tudinal and itpproxir. radial ^■•ri-'- ■^' r ' , I'nuo fiv.; 



soclionG :.md an ultii-iate mari^inal cell ol Uie sixtli gn.. . 

 Each of tliecG divisions fonns rjlorome, nerililfira rjid donna- 

 togen L.yers, ^.ai- tiie a:.ic.l biTidle oi the petiole is foiTfi- 

 &d from tlie pleromo of tJie firot foiTr section:. Aiv- CcJi:.1s 

 appear betv/een tlie peri'blem and derniatogen in a definite 

 rf-iKiber, c\nd tiie partitions betv/cen '.liese, vhich are de- 

 rived from tile peri'blem, have many intercellular openir^s 

 through them at maturity'-. Trichomes are formed from tlie 

 epiderm^il cells in a very regular arrangerncnr. Certain 

 rov/s 01 thoperiblem cells "becone speciali.-ed as tarinin 

 reservoirs. Tuc; pirmae or divisions of th.e 1 Lamina arise 

 as a result of the continued activity of the marginal cells 

 of certain segments, but their limit?, do no' correspond 

 exactly v/ith those of the segments* 



Tlie sporocarp arises from a single uliimate marginal 

 cell of the secon.L segment of the leaf, as a lateral "brLmcli 

 of the latter, when i. consists of only six or seven seg- 

 ments on each side. Tlio second sporocarp usuxilly arises 

 in the sarae v/ay from ono of the basal marginal cells of the 

 first one, and is thus a seconda -y briaich of the leaf. 

 The apical cell is tna^svorsc in positior-., vjiy gro--' "b^' 



this continues till about tv/en' y four serTnents have been 



