181 



FEENS and FLOWEEING PLANTS : a CHAPTEE 

 in EVOLUTION. 



AN ADDRESS BY 



D. H. Scott, M.A., Ph.D., F.E.S., 



HONORARY KEEPER OF THE JODRELL LABORATORY, ROYAL GARDENS, KEW. 



[Read May 8th, 1896.] 



Absteact. 



The object of the lecture was to show how much light 

 has been thrown on the evolution of certain groups of 

 Flowering Plants, by modern work on fossil botany. 



The order Cycadese, now represented only by 9 genera 

 with about 70 species appeared to be the remnant of what 

 was once a great class of plants, with wide-spreading 

 affinities. 



The first part of the lecture was devoted to plants from 

 the Palaeozoic rocks, which combine the characters of Ferns 

 with those of Cycads. Lijginodendron, a Coal-measure 

 fossil the structure of which was discovered by the late 

 Prof. Williamson, was shown to have a stem which was 

 essentially that of a Cycad, while the leaves, both in 

 form and structure, were entirely Fern-like, belonging 

 to Brongniart's genus Sphenopteris. The adventitious 

 roots, when young resembled those of Marattiaceae, but 

 subsequently grew in thickness like the roots of modern 

 Gymnosperms. Heterangium was also described, and 

 proved to stand nearer to the Ferns (resembling those of 

 simple structure, such as Gleichenia), as might be 

 expected from its greater geological age, one species 

 appearing in the Burnt island beds, at the base of the 

 Carboniferous formation. 



