CHAPTER X 



PTERIDOSPERMEAE 



Lyginodendreae 



We now leave the Ferns, and pass on to the Pterido- 

 spermeae, a series of forms which are among the 

 most interesting made known to us by fossil botany, 

 for they unite in their organisation the characters of 

 two of the main divisions of the Vegetable Kingdom — 

 the Seed-plants and the Ferns. 



It has long been recognised that many of the fronds 

 from the Carboniferous strata, commonly described as 

 those of Ferns, are subject to grave suspicion of not 

 having really belonged to the class Filicineae. Such 

 suspicions attach not only to the so-called genera 

 Alethopteris and Neuropteris, and to a large part of 

 Sphenopteris ', but to an actual majority of the Fern-like 

 fronds. The plants in question have never been found 

 with recognisable fructifications of a Fern-type, whereas 

 in the accepted fossil Ferns, specimens with sori 

 occur in a fairly large proportion of cases. It was 



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