merged plimts, liov/ovor, sliov.'s r.ome ludf-grov/ii cporociu^p" 

 or noniuil iippeciriinco, tmd many more o." i.hc s:Lmo or cncillor 

 Gisc which have evidently been arrect'jd in their acveiop- 

 ment, and appear chriinken or . ithered. The leaves on v/hicli 

 those are borne have gone on in their development, and 

 v/e may thus find on full grov/n leaves cpo/ocarpa of the 

 same size as those found on other leaves of v/hicli the 

 pinnae have not yet unfolded. There is thus, on the 

 whole, no great regulcirity in the retardation in develop- 

 ment of the fertile or sporocai-p bearing leaves. 



Of tlie origin of the sporocarp of Mars ilia, Bischoff 

 (*28) says, tiiat it arises as a slight prominence oi' 

 papilla on tlie anterior side of the base of the petiole. 

 Mettenius (*-L-C) on 'ohe other h.and, states that it arises 

 endogenous ly and le.ter breaks through the epidennis of 

 the petiole, to form a projecting solid mass of tissue 

 in the interior of which the various inteiTi;.l stiT.ctuj^es 

 of the capsule are formed. The youngest sporocarps found 

 by Russo (*72), h.ad a t\7o sided a.pical cell, but were 

 already differentiated intoasterile stalk tind a fertile 

 tip or capsul':, being probably in about the same stage as 

 that sho n in Fig. 42. He ti-aced the development of the 

 soral cimals, stating that they arise b}^ t-hc splitting 

 apart of ceH.ain cells in the interior of tiie capsrJo, 

 cind tlie development of pits on tlio ventral surface o ' t};is 



