OF LOWER GREENSAND PLANTS. 259 



fossil species (principally leaf-impressions) have been described. 

 While it seems certain that in some part of the globe, Angio- 

 sperms must have existed in Jurassic times, if not earlier, no 

 reliable determinations of Angiosperms appear to have been 

 made (with the possible exception of a few Erench impressions) 

 before the Cretaceous. 



A useful critical account of the earlier reputed Angiosperms 

 is given by Berry (1911), to which reference should be made. 

 He says (p. 149) : " There is fairly satisfactory evidence of 

 Angiosperms in beds which are classed as Aptian, and by the 

 close of the Albian dicotyledons became a considerable element 

 in the floras." Regarding the so-called earlier Angiosperms, the 

 Ficopliyllum, etc., of the American Potomac, of which so much 

 has been made by some authors, even since the publication of 

 my paper (Stopes, 1912), Berry " is convinced that these forms 

 are not Angiosperms .... and it would do no violence to the 

 known facts if some of them were referred to the Filicales." 

 The discovery of Angiosperms of Aptian age in England (see 

 Stopes, 1912) extended the range of the early forms, and called 

 in question the assumption that the Angiosperms originated on 

 the American borders of the North Atlantic and had not spread 

 to Northern Europe by that time (see Chamberliu & Salisbury, 

 1906). 



The problem of the origin of the Angiosperms has attracted 

 much interest and hypothetical dissertation. Facts, however, 

 are needed, and unfortunately hitherto the few available early 

 fossils have been leaf-impressions, which are difficult and 

 unsatisfactory evidence. 



In the present volume further new species of dicotyledonous 

 woods are described. They bring into prominence the lack of 

 real knowledge concerning the systematic anatomy of woods. 

 At present it is impossible to obtain, regarding the living 

 forms, the information necessary for palreontological work. 

 Until the Dicotyledonous woods have been given the careful 

 attention which has been expended on the woods of Conifers, 

 no satisfactory progress in the palaeontology of tho earliest 

 Angiosperms can be made. It is my opinion that, as in the 

 case of the Conifers, the details of the medullary ray-cells will 

 prove of considerable diagnostic value. I am not aware, how- 

 ever, of any publication which attempts to illustrate even the 



