﻿22 SCOTT, Early History of Seed-bearing Plants. 



of view, is Poroxylon, investigated with wonderful 

 thoroughness by Messrs. Bertrand and Renault nearly 

 20 years ago (Bertrand and Renault, '86). Here, as in 

 Cordaites, the structure of all the vegetative parts of the 

 plant is known with all the detail that could be desired, 

 but we are as yet ignorant of the nature of the repro- 

 ductive organs. The thick, simple leaves have a structure 

 comparable in all essential points to that of the leaves of 

 Cordaitese ; as in them, the vascular bundles are like the 

 foliar bundles of Cycads. The roots also resemble those 

 of Cordaite^e and have the typical structure of Gymno- 

 spermous roots. The stem, however, has essentially the 

 structure of a Lyginodeudron stem, that is to say, strands 

 of primary wood, wholly or mainly of centripetal develop- 

 ment, are present round the pith, and pass out in pairs, 

 through the secondary tissues, to form part of the bundles 

 supplying the leaves. Here then we have a clear combi- 

 nation of Cordaitean characters with those of a Pterido- 

 spermous genus. Poroxylon, however, has so far only 

 been known from the Permian, and might thus be thought 

 too late in appearance to illustrate the origin of so ancient 

 a group as the Cordaiteae. It is therefore of interest to 

 know that quite recently a plant has been discovered by 

 Mr. Lomax in the lower coal-measures at Shore, Little- 

 borough,* in this county, which shows, in perfect preserva- 

 tion, all the essential characters of the French Poroxylon y 

 and, so far as a preliminary investigation has shown, will 

 prove to be a new species, or, at least, a close ally of that 

 genus, from a much lower horizon than the other repre- 

 sentatives of the group. 



Further, stems have been known for some time of still 

 greater age, belonging to lower carboniferous horizons, 



* A locality remarkably rich in petrified plant-remains, now opened up 

 to pahvobotanical exploration by the generosity of the owner, Mr. W. II. 

 Sutcliffe. 



