SPHENOPHYLLEAE 1 1 3 



spikes show the sporangia grouped in fours, the groups 

 resting on the upper surface of a repeatedly forked bract, 

 below the points of bifurcation (Fig. 48). This form is 

 interesting from its analogy with the fructification of the 

 recent Tmesipteris, while in 5. trichomatosum} on the 

 other hand, the arrangement seems to have been a very 

 simple one, the sporangia appearing to be sessile and 

 solitary on each bract in the axils of the bracts. It is 

 quite possible, however, that a short pedicel was present. 



Fig. 48. — SpJuTiofihylhim majus. Forked sporophyll bearing four sporangia. 

 After Kidston. 



The four most important types of fructification are 

 those of S. Dawsoni, Bowmanites Romeri, S. fertile, and 

 S. majus. 



It follows sufficiently, from what has already been 

 said, that Sphenophyllum represents a perfectly distinct 

 group of plants, of which all the parts — stem, leaves, 

 roots, and fructification — are known in one species or 

 another. There is no longer any room for the idea, 

 once sanctioned by good palseobotanical authorities, that 



1 I am indebted to my friend, Mr. R. Kidston, F. R.S. E., for informa- 

 tion as to these species. On Sphenophyllum trichomatosum, see Mr. 

 Kidston's paper in Proc. Royal Phys. Soc. of Edinburgh, vol. ii. 1891, and 

 on .S. majus and other species, his Carboniferous Lycopods and Sphenophylls, 

 Trans. Nat. Hist. Soc. Glasgow, vol. vi. Part i. 1899-1900. 



