CALAMOSTACHYS 59 



The evidence from comparative anatomy is also of 

 considerable importance. The anatomy of the axis of 

 the British forms of Calamostachys, which we have 

 described fully above, although it agrees sufficiently 

 well with that of Catamites to allow of the probability 

 of relationship, is not exactly that of a Calamitean 

 stem. It is very interesting to find that in some of 

 the Continental species this difference does not exist. 

 They combine the exactly typical anatomy of the 

 Calamitean stem with the external morphology of a 

 C alamo stachys. This is the case, for example, in the 

 fructification originally described by Renault under the 

 name of Bruckmannia Grand Euryi, which is, to all 

 intents and purposes, a Calamostachys, and is placed 

 by Count Solms-Laubach l in that genus. 



In this case the anatomy of the axis is peculiarly 

 well shown ; there is a fistular pith, surrounded by a 

 ring of eighteen collateral vascular bundles, and beyond 

 that the cortex. Each bundle has a canal, perfectly 

 defined, at the inner margin of its wood. In fact, the 

 anatomy of the axis is that of a young stem of 

 Catamites, so that the species Calamostachys Grand'- 

 Euryi completely removes any anatomical difficulties 

 we might find in referring Calamostachys to Calamitean 

 stems. At the node each bundle gives off two strands 



xxii.-xxiv., in Abhandlungen zur geologischen Specialkarte von Preussen, 

 Band v. 1884. In the plates cited the structure of C. Ludwigi is 

 magnificently illustrated. 



1 Fossil Botany, English edition, p. 329. M. Renault named this 

 fructification Artkropityostachys Grand' Eury i ; Bassin houiller et permien 

 d'Autun.et d'Epinac,flore fissile, Part ii. p. 135, Plate lxii., 1896. See 

 also his Cours de botanique fissile, vol. ii. p. 136, Plates xxi. and xxii., 

 1882. The structure of this cone is preserved with extraordinary 

 perfection. 



