MARATTIACEAE 



[CH. 



of them the sporangia of the single sorus are developed simultaneously, 

 which is a primitive state (Vol. I, Chapter Xiii). 



Fernlike fronds bearing sori similar to those of existing Marattiaceae are 

 found in the Upper Palaeozoic Floras (Fig. 393). It is, however, in the older 



■Fig- I9i- ^. -^1 Scolccopteris elcgans Zenker, from the Lower Permian. A, transverse section of a fertile 

 pinnule, enlarged (after Zenker). B, Scolecopteris polyiiiorpha Brongn. from the Stephanian : 

 longitudinal section of a fertile pinnule, enlarged (after Grand'Eury). C, D, E, Asterotheca. 

 C, A. Miltoni Artis, from the Westphalian: fertile pinnules ( x 2). D, synangium of Asterotheca 

 ( X about 6). E, longitudinal section of a pinnule of Asterotheca, traversing three synangia, 

 enlarged. (After Grand'Eury, from Zeiller's Palaeobotanique.) 



Mesozoic rocks that we first encounter Ferns which agree closely in habit, 

 as also in the characters of the sori with the recent representatives of the 

 Family, while the maximum development of these Ferns as we now know 

 them, seems to have been in pre-Cretaceous times (Seward, Hooker Lecture, 

 1922). Among Palaeozoic fossils radially constructed stems of greater 

 length, but showing strong analogies with the stems of modern Marattiaceae, 

 have long been known under the name 

 of Caiilopteris when the external surface 

 is seen in the form of impressions: or of 

 Psaroniits when the internal structure is 

 preserved. Among other points of simi- 

 larity roots may be found traversing their 

 cortex in the same way as in Marattia 

 or A ngiopteris. They have been found to 

 be related to Pecopterid foliage bear- 

 ing characteristic fructifications (Zeiller, 

 Elements, p. 120). Such stems were 

 arborescent and thick. The leaves were 

 sometimes distichous {Megaphytoii), 

 sometimes tetrastichous, in others again 

 spiral : this last corresponds most nearly to 

 the leaf-arrangement in the living genera. 

 The general character of such stems is 

 suggested by Fig. 394. The conclusion 

 seems clear that Ferns of arborescent character, but with leaves of different 

 outline from the living Marattiaceae, existed in Palaeozoic times. 



The Marattiaceae are relatively massive in the construction of their parts, 

 and this appears especially in the adult state. It has been shown by Charles 



Fig. 394. Diagrammatic view of a trunk of 

 a Fern from the Coal Measures, showing 

 above the external cortex with petiolar 

 scars (Caiilopteris), and below the woody 

 cylinder with scars corresponding to the 

 foliar strands, and their sclerotic sheaths 

 {Ptychopteris). Reduced to \ natural size. 

 (After Zeiller.) 



