PALAEOSTACHYA 63 



heterospory is, however, proved in the case of another 

 species perhaps referable to Palaeostachya} 



In Palaeostachya gracilis, according to Renault's 

 observations, the number of sporangiophores in the 

 whorl is about half that of the bracts, while the number 

 of vascular bundles in the axis is equal to that of the 

 sporangiophores in a whorl. In its anatomy, the axis 

 closely resembles a young Calamitean stem. 



A fructification belonging to the type of Palaeo- 

 stachya was described by Dr. Williamson for the first 

 time in 1869, 2 and subsequently much more fully in 

 1887. 3 This strobilus he called the " true fructification 

 of Catamites" and, for many years, he refused to admit 

 any other fructification as properly belonging to 

 Catamites, the reason being that in this " true fructi- 

 fication " of his, and, as he thought, in no other, the 

 Calamitean anatomy was manifest in all its essential 

 points. In cases where we have both the peduncle 

 and the axis, the former has in all respects Calamitean 

 structure, including a secondary zone of wood, which 

 dies out as the axis itself is approached. This form 

 was called by Dr. Williamson in his last memoirs 4 

 Catamites pedunculatus . It was distasteful to him to 

 give any other generic name than Catamites to a 

 fructification which he felt so sure belonged to that 

 genus. It is, however, more convenient to retain special 



1 Renault, Flore fossile cCAntun et tfEpinac, Part ii. p. 77, Plate 

 xxix. Figs. 6 and J. 



2 " On a New Form of Calamitean Strobilus," Mem. Lit. and Phil. Soc. 

 of Manchester, 1869. 



3 "Organisation of Fossil Plants of Coal-measures," Part xiv., Phil. 

 Trans. 1888, B. 



4 See Williamson and Scott, "Further Observations, etc.," Part i., 

 Phil. Trans, vol. 185, B, 1894, p. 916. 



