66 BOTANY 



were such large number of fern leaves among the 

 fossils representing the epoch. The impressions of 

 these fern leaves were sometimes remarkably perfect, 

 and showed the form of the divided fronds which in 

 externals so much resemble modern forms. The first 

 clue to the discovery that these plants were not what 

 they seemed resulted from the study of the specimens 

 which have their internal cells petrified. Under micro- 

 scopic examination their internal anatomy \vas found 

 to be much more highly organised than that of modern 

 ferns. The discovery from petrified remains that these 

 plants bore seeds of complex structure was followed 

 by the recognition in impressions that several other 

 species supposed to be ferns also had seeds attached 

 to their fern-like leaves. There are now grounds for 

 supposing that a large proportion of the " ferns " of 

 the Coal Measures belonged to the higher seed-bearing 

 group of the Pteridosperms. This extinct group 

 bridges one of the great gaps in the series of modern 

 plants. Among those which are still living to-day there 

 are almost none which indicate the connection between 

 ferns and seed-bearing plants. Clear-minded botanists 

 some time ago had seen some obscure points of structure 

 that hinted to them that some such connection must 

 at one time have existed, but the exact form which 

 it took, and the time of its existence, were matters 

 purely of the imagination. The Pteridosperms and all 

 that they reveal are matters of fact. 



It must not be supposed that these are the only 

 trophies of the study of modern palaeobotany. Every 

 fossil plant that is discovered helps to fill in the blank 

 spaces in the great genealogical tree, and many of them 

 show quite as interesting or unexpected features as do 

 the fossils just described. 



