2 2 PEOCEEUINGS OF THE 



trace bundles to the central axis was correctly followed ; the 

 restoration of the structure in the solid which he gives (P). 21, 

 fig. 4) is remarkably accurate. In opposition to Lindley and 

 llutton, who had concluded that Lejndodeiulron was intermediate 

 between Conifera) and Lycopodiace;e, Brongniait showed that 

 the structure is essentially diflerent i'roni that of any Dicotyledon, 

 gyinnospennous or angiosperinous (p. 44). lie points out the 

 differences from Lijcopod'mm and tSthujiiidla, and shows that 

 the best anatomical comparison is with J'sUotum and Tmesipteris. 



He further points out the identity of the rayed or scalariform 

 vessels of Lepidodendmn with those of Lycopods, and the small 

 size of the peripheral vessels in both, and concludes : " Thus, by 

 the internal structure of their stems, as by their external form, 

 their mode of branching and the arrangement of their leaves, the 

 Lepidodendrons agree almost completely with the Lycopodiaceffi, 

 and could be nothing else but arborescent Lycopods" (p. 46). 

 His whole treatment of the subject is on sound modern lines. 



He then asks the question, "Is the same analogy to be met 

 Avith in their mode of reproduction? " 



He begins by citing cases where the cones (Lepidostrohi) had 

 already been found in connection with species of Lepidodendron — 

 he found that they were borne on the ends of branches, like 

 Lj/copodiinn cones on a large scale, or like the cones of Araucaria. 

 He was much puzzled about the position of the sporangium or 

 capsule, which from the analogy of Lycopods and Conifers 

 (" families between wliic-h all botanists are agreed in placing the 

 Lepidodendrons ") should be on the upper surface of the scale 

 [he ignores the nude cones of Coniferaj here]. Having no petrified 

 specimens to work with, lirongniart at that time completely 

 misunderstood the position of the sporangium, which in fact he 

 had never seen, or had perhaps confused with the lateral wings 

 of the scale. Lindley and Hutton, it is true, had already 

 observed the sporangium in Lepidostrofms ornatus, but they had 

 described it as a " seed " *, so that Brongniart not unnaturally 

 suspected a confusion with the cones of Araucarian Coniferjie. 



He was very cautious about the supposed relation of Lep>ido- 

 dendron to Conifers, regarding it as extremely remote. The 

 former group, he says, is not intermediate between Lycopods 

 and Conifers, but is at most a Lycopodiaceous genus tending to 

 establish the first link in a series forming the passage between 

 the two families (p. 55). Some of his arguments against a nearer 

 relation, especially those drawn from the mode of branching and 

 the structure of the wood, are well worthy of consideration. 



Brongniart was distinctly less fortunate in his view of the 

 petrified tree-fern stems known as Psaronius, which he regarded, 

 on what seem to us very weak grounds, as representing the base 

 of Lycopodiaceous stems. AVith all his good intentions, his 

 knowledge of Pern-anatomy was not yet wide enough to guide 



* 'Fossil Flora,' toI. i. pi. 20. %. 2a, p. 83. 



