Manchester Memoirs, Vol. liv. (1910), No. H, 11 



to me in the highest degree probable that the primitive 

 position of the bracts was similarly opposite the bundles, 

 they having reached their present position by slight 

 lateral shifting of each whorl to right or left. 



As it has been clearly pointed out before, no definite 

 relation can now subsist between the bracts and either 

 the sporangiophores or the bundles, since the number of 

 the bracts in a whorl is variable, and its variation bears 

 no definite relation to the number of bundles or spor- 

 angiophores. Thirteen appears to be the commonest 

 number of bracts. 

 PJiylogenetic Position of the Cone. 



This question may be briefly discussed in the light of 

 the present communication. 



Neglecting the doubtful types Bornia and Cingidaria, 

 we have three types of Calamitean fructification, Calaino- 

 stachys, Stachannularia, and PalcEostacJiya. The type 

 which Weiss (Weiss '76) describes as Stachaiiimlaria is de- 

 fined as having its sporangiophores inserted slightly above 

 the middle of the internode, and by the sporangiophores 

 possessing a wing-like-expansion on their upper side, 

 which, in some cases, appears united with the bracts of 

 the whorl above. It seems probable that this is really 

 the same type which Renault has described from structural 

 material as Briickniannia Grand' Eiiryi s.nd Bruckniannia 

 Decaisnei, in which the sporangiophores are similarly 

 adherent to the bracts of the next superior whorl. If so, 

 this type is essentially similar to Calaniostachys. Palceo- 

 stachya I have elsewhere fully described (Hickling, :07). 



So far as is known, the successive whorls of sporangio- 

 phores in all types of calamite cone were superposed, and 

 from their constant relation to the primary vascular 

 bundles this raised a strong presumption that the bundles 

 were in all cases non-alternating. This was certainly the 



