ii8 SCIENCE PROGRESS. 



nicinner adduced rests on the best foundation, and must 

 indubitably lead to a fuller recognition of the value of 

 palaiobotanical research as a factor of primary importance 

 in phylogenetic inquiries. 



In addition to the various points suggested in the de- 

 scription of these two extinct plants, and referred to in the 

 foregoing summary, there are at least two reflections worthy 

 of mention. In the first place, the work of many palseo- 

 botanists has clearly emphasised the need and importance 

 of a more intimate acquaintance with the morphology of 

 existing Cycads. Secondly, it would appear certain that 

 among the numerous leaves of Palaeozoic plants which it 

 has been the general custom to regard as typical fern fronds, 

 there must be some which belong to stems in which 

 Cycadean characters more or less predominated. The 

 probable connection of many "Cycadean" fronds with 

 Bennettitean stems illustrates an analogous case among 

 Mesozoic plants. 



A word of the highest praise is due to Mr. Brebner for 

 the admirable illustrations accompanying Williamson and 

 Scott's memoir ; ^ it would be difficult indeed to obtain more 

 accurate and artistic reproductions of the almost incredible 

 perfection of detail exhibited by sections of Carboniferous 

 plants. 



A. C. Seward. 



^ Williamson, W. C., and Scott, D. H. " Further observations on the 

 Organisation of the Fossil Plants of the Coal-Measures." Part iii. Lygino- 

 dendron and Heterangium. Phil. Trans. Royal Society, vol. clxxxvi., B., 

 pp. 703-729, pis. 18-29, 1896. 



