72 STUDIES IN FOSSIL BOTANY 



palaeontologist, Stur, gives a good idea of the habit of a 

 leafy branch, and in Fig. 31a single, repeatedly forked leaf 

 is shown. M. Grand'Eury has discovered fructifications 

 resembling the cones of living Equisetaceae, from the 

 French Coal-measures, and Mr. Kidston has described, 

 under the name of Equisetum Hemingwayi, a large cone, 

 which presents the external characters of a fructification 

 of the recent genus. There is altogether a considerable 

 amount of evidence to show that fructifications of the 

 Equisetum type already existed in the Coal-period, but 

 unfortunately none of the specimens in question have 

 their internal structure preserved. The Permian plant 

 known as Phyllotheca deliquescens, has a fructification 

 presenting some analogies with Potkocites, the long 

 fertile spikes being interrupted at intervals by whorls 

 of sterile leaves. A similar condition occurs as 

 an abnormality in recent species of Equisetum. 



6. Macrostachya. — In addition to these well- 

 characterised types, we have various fructifications 

 which have been referred to Calamarieae, but as to 

 which our information is contradictory and scanty. 

 Among these it is only necessary to mention the genus 

 called Macrostachya, the cones of which are of great 

 size, attaining 8 inches in length by an inch or more 

 in diameter (see Fig. 32). They were often borne in 

 whorls, on stout stems with typical Calamitean structure, 



as exactly that of an ordinary Calamite, of the kind in which the medullary 

 rays become bridged over by interfascicular wood. The roots were of the 

 " Astromyelon" type. See Renault, Flore fossile (fAutu.n et cCEpinac, 

 Part ii. p. 80, Plates xlii. and xliii. ; and Solms-Laubach, Botanische 

 Zeitung, 1897, p. 219. It is possible, however, that the Lower Carboni- 

 ferous Calamarian stem, with centripetal wood, described on p. 36, may 

 have belonged to an Archaeocalamites. 



