288 PROTOCYATHEACEAE [CH. 



upright Cyatheoid series, and tiiat of living Ferns they most nearly represent 

 the forerunners of that great dendroid Family. Lophosoria shows the 

 creeping habit in its runners: but in their upturned tips they demonstrate 

 a direct passage to the dendroid state. The vascular system supports this, 

 for while the runners are solenostelic, the upright axis shows steps towards 

 the dictyostely seen in Alsophila and CyatJiea. The leaf-trace of Lophosoria 

 passes off undivided as in G. pectinata, but it may be disintegrated later, 

 thus anticipating temporarily, but not permanently, what is a usual feature 

 of the Cyatheaceae. In these stelar characters G. flabellata, G. pectinata, 

 Lophosoria, and Alsophila form a naturally progressive series from protostely 

 to dictyostely. In the dermal appendages G. pectinata and Lophosoria are 

 alike, except that the former has stiff branched bristles that are not found 

 in the latter. Both differ in this point from the scaly Cyatheaceae. 



The habitof the \e^.{ oi Lophosoria as a whole is Cyatheoid, not Gleichenioid : 

 but the fertile pinnule is distinctly Gleichenioid, the position of the superficial 

 sorus on the anadromic veinlet of the ultimate pinnule being identical in 

 both. Both have a simple sorus without indusium: but while G. pectinata 

 with its median dehiscence had advanced by the crowding of its sorus to the 

 point of inefficiency in shedding its spores, Lophosoria has attained to lateral 

 dehiscence, so that there is no risk of a mechanical dead-lock. In both 

 the sporangia remain short-stalked. In point of spore-number while 6^/i?zV,^^«/« 

 stands high, Lophosoria has an output reduced to the lower number seen in 

 many Cyatheoids. Lastly the prothallus of Lophosoria corresponds to that 

 oi Alsophila. The whole effect of these comparisons is to show \hz.t Lophosoria, 

 though clearly one of the Cyatheoids, stands aloof from them, and corresponds 

 rather with G. pectinata. It may be held as one of the advanced Simplices, 

 of similar ancestry to the Gleicheniaceae, which while retaining many of the 

 same features as they possess, has adopted two distinctive innovations, viz. 

 an upright habit, and a lateral dehiscence of its sporangia. But these are 

 prominent characteristics of the Cyatheaceae, and notably of Alsophila, 

 with which genus it has habitually been classed. 



Metaxya ro strata Presl 



Metaxya rosirata Presl is a handsome South American Fern, with leaves 

 a metre long, borne on its creeping stem. Buds are frequently borne on the 

 abaxial side of the leaf-base, which may grow out into branch-rhizomes. 

 The leaves are simply pinnate, with broadly lanceolate pinnae 6-12 inches long, 

 and serrate near to the tip, suggesting an origin by webbing from a doubly 

 pinnate type. The veins are parallel and occasionally forked, but never fused. 

 The sori form an irregular series on either side of the midrib : on some veins the 

 sorus lies nearer to, on others further from the margin, and not uncommonly 

 two or more may be borne upon a single vein. Their position is consequently 



