2 Wkiss, Root-apex and Young Root of Lyginodendron. 



pointed out elsewhere, Professor Chodat/ of Geneva, 

 throws some doubt on the Cycadian affinities even of 

 Lyginodendron and Heterangunn, and it becomes of in- 

 terest, therefore, to investigate detailed points of anatomy 

 in further elucidation of the structure of any of the 

 members of the Pteridospermae. 



Among some of the most beautifully preserved plant 

 remains from the calcareous nodules found in and im- 

 mediately above some of our Lancashire coal-seams are 

 the young root-tips of Lyginodendron. One of these 

 was figured by Stopes and Watson in their memoir " On 

 the Present Distribution and Origin of the Calcareous 

 Concretions in Coal Seams," (See Pi, Fig. i),"" as indica- 

 ting the very perfect preservation of delicate growing 

 tissues of some of the Coal Measure plants. I have 

 for some time been collecting preparations of these 

 root tips with a view of their further study. In most of 

 our recent ferns belonging to the Leptosporangiatae, the 

 root-apex is occupied by a single cone-shaped apical 

 cell, while in the Marattiaceae, which are now generally 

 regarded as some of the more ancient of living ferns, a 

 group of initial cells is responsible for the further growth 

 of the root. The Osmundaceae occupy in this respect an 

 intermediate position between the bulk of the Lepto- 

 sporangiate Ferns and the Marattiaceae. For as Bower 

 has shown,-' in the roots of Osmunda and Todea various 

 irregular and intermediate conditions have been found 

 between the Marattiaceous type, with four prismatic 

 initials, and that of the Leptosporangiate Ferns, where 

 only one occurs. 



^ Chodal R. Les Pleropsides des temps palaeozoiques. Arcliives des 

 Sciences physiques et naiurclles, Geneve, Tome XXVI., 1908. 



- Phil. Trans., vol. 200, 1908. 



" Bower, F, O. Annals of Botany, vol. V., 1S89, p. 109, and also 

 "The Origin of a Land Flora," 1908, p. 650. 



