54 THE ORIGIN OF THE SEED-PLANTS 
one member, at least, of the Cycadofilices was a seed-bearing plant. 
The seed itself proved to be of a complex structure, most nearly com- 
parable to the seeds of the Cycadaceæ. The name Pteridosperms was 
then proposed for those Cycadofilices in which there was evidence of 
the seed-habit. 
Further examples of ,Seed-Ferns’’ were soon brought to light. In 
1904 Dr. KipsTon discovered large seeds, of the size of a Hazel-nut, 
borne on the fronds of Neuroßteris heterophylla; here the evidence was 
direct, though the structure was not preserved. In the same year Dr. 
DaviD WHITE showed that his Aneimites (Adiantites) fertilis, from the 
Lower Pottsville beds of West Virginia (correlated with our Millstone 
Grit), was a seedbearing plant. The small flattened seeds are borne di- 
rectly on the Maidenhair-like fronds. Then, a year later, Grand, Eury 
discovered the fronds of Pecopteris Pluckeneti, previously an unquesti- 
oned Fern, covered with hundreds of winged seeds, resembling those of 
the Gymnospermous trees known as Cordaiteæ. 
Other discoveries followed, and in numerous cases, besides those 
clearly demonstrated, there was reason to suspect that so-called Palæo- 
zoic Ferns were in reality members of the Spermophyta. In fact the 
conclusion was soon reached that an actual majority of the , Carbonife- 
rous Ferns!’ were not Ferns, but Pteridosperms 1). 
So far there is nothing to criticise. For a time there may have been a 
tendency to make too little of the true Ferns of the Carboniferous 
period, but this was only a temporary aberration, and the general 
result as to the importance of the , Seed-Ferns” remains‘unshaken. 
A further conclusion, however, was drawn by some of those who were 
interested in these discoveries. The idea got abroad that the Pteri- 
dosperms were „Ferns which had become Spermophytes,” the popular 
name ,,Seed-Ferns” thus being taken in a literal sense. The present 
writer is one of those responsible for this interpretation of the facts. 
The Fern phylum was said to have been the source from which the 
great majority, if not the whole of the Seed-plants were derived 2). This 
generalisation was of course dependent on the assumption that the Pte- 
1) The evidence is brought together in Seward’s Fossil Plants, Vol. III, 1317 
chaps. xxix-xxxi, and in the present writers’ Studies in Fossil Botany, Vol. II, 2nd 
edition, 1909, chaps. x. and xi. The latter account will shortly be brought up to 
date in a third edition. 
2) Studies in Fossil Botany, Vol. II, 2nd edition, p. 638. 
