252 HISTORY OF BOTANY 



with the petioles and leaves of a fern and the seed of a 

 Spermatophyte. What, then, were the male organs or 

 stamens like ? 



Among the ancient fem-Hke fronds that were still 

 regarded as remains of true ferns were types representative 

 of our modern Marattiaceae. Among these was a genus, 

 Crossotheca, whose pinnules bore half-a-dozen or more 

 pointed microsporangia. The Scotch palaeobotanist, 

 Kidston, made a detailed examination of this frond in 

 1905, and proved that it was not a Marattia but the 

 male frond of Lyginodendron, so that, while the mega- 

 sporangium had adopted seed characteristics, the micro- 

 sporangium had remained fern-hke. 



The labours of palaeobotanists during recent years 

 have considerably extended our knowledge of this ancient 

 family, now known as Pteridosperms, and several other 

 series of stems, leaves, and seeds have been correlated 

 and pieced together, but for details as to these I must 

 refer you to Scott's Fossil Botany wherein you will find 

 the evidence given in full. As to the affinities of the 

 Pteridosperms I cannot do better than quote some 

 sentences from Scott's article in the Progressus ret 

 botanicae, from which, indeed, I have already read you 

 an extract. 



" A more fundamental question is that of the relation 

 of the Pteridospermeae to the Cryptogams. As has 

 been sufficiently shown in the preceding pages, all the 

 characters in which the Pteridosperms show Cryptogamic 

 affinities, whether in anatomical structure, in the morpho- 

 logy of the sporophyll, or in the nature of the male 

 fructification, point clearly to their derivation from 

 ancestors belonging to a FiHcinean stock. They have 

 been described as ' Ferns which have become Spermo- 

 phytes,' and the phrase is appropriate. When, however, 

 we come to inquire into the characters of the FiHcinean 

 group from which the Pteridosperms arose, we find that 

 our data are insufficient. They are themselves, in all 



