38 PROF. W. C. WILLIAMSON ON THE 



mitaceas, but occupying a position between the latter 

 group and the Lycopodiaceae, as indicated by the organ- 

 ization of the central axis, which, as we have seen, is 

 eminently Lycopodiaceous. This conclusion as to the 

 botanical position of these objects has been arrived at from 

 the study of the examples in my own cabinet ; but I am 

 glad to find that my friend M. Grand'Eury, of St. Etienne, 

 in France, has arrived at a similar conclusion from the 

 study of specimens found in his own neighbourhood. 

 He ends his reasonings on the subject by amrming, u On 

 peut done en conclure que les Asterophyllites arbores- 

 centes sont issues, non des Calamites, mais des tiges folii- 

 feres organisees comme elles" (" Observations sur les 

 Calamites et les Asterophyllites, par M. Grand'Eury." 

 Comptes Rendus, torn, lxviii.). One point of difference 

 between these two types upon which M. Grand'Eury relies 

 has, I think, no existence. He says that the Asterophyllites 

 have "leurs feuilles attachees au-dessus des lignes d' ar- 

 ticulation et, ce qui est bien autrement significatif, leurs 

 rameaux secondaires inseres a Taisselle des verticilles foli- 

 aires, et non au-dessous, ce qui aurait lieu s ; ils avaient 

 P organisation des vraies Calamites" (loc.cit.). These 

 supposed differences, as I have shown in a memoir re- 

 cently laid before the Royal Society of London, do not 

 exist. 



I think we may conclude that, of the three types of Volk- 

 mannia of which we know the organization, two are now 

 collocated with their respective stems with a fair degree 

 of probability. There yet remains the Volkmannia Binneyii 

 demanding a parent axis upon which it can hang. This 

 latter strobilus and the primary subject of this memoir 

 obviously belong to two distinct genera of plants. The 

 former has its sporangiophores arranged in verticils of 

 stiff processes, projecting from each alternate node, and at 

 right angles to the axis, the intermediate nodes giving off 



