810 REPORT— 1902. 



proximity to several roots. This shows that it has been a plant of considerable 

 growth. 



The position of the roots also shows they must have been aerial roots, and not, 

 as generally accepted, basal or confined to the basal regions of the stem. 



There is one other point we want to make clear, and that is the generative 

 organs of the plant. So far they have escaped our notice, but I expect that we 

 may before very long be in a position to state definitely what were the fructifica- 

 tive or the regenerative organs of these most interesting fossil plants. 



The detailed description of the above specimen is left in the hands of 

 Dr. D. H. Scott. 



5. Sporangiopliores as a Chie to Affinities among Pteridophyta. 

 By D. H. Scott, mX, Ph.D., F.R.S. 



Some years ago the writer suggested the probability of an homology between 

 the ventral sporangiophores of Sphenojjhylluni or Cheirostrobus and the similarly 

 placed synaogia of the Psilotea3 ; on this ground, among others, an affinity be- 

 tween the fossil and the recent family appeared tenable. This view has recently 

 been supported by Professor Thomas of Auckland, N.Z., on evidence drawn from 

 certain remarkable variations which he observed in the genus Tmesipteris. In the 

 present communication the evidence from comparative structure in the typical 

 forms is considered. 



On the view suggested, the synangium of the Psiloteaj is neither a reduced 

 strobilus nor a septate sporangium, but a ventral sporangiophore bearing a variable 

 number of sporangia, normally two or three, according to the genus. 



If this interpretation holds good, the nearest affinities of the Psilotere would be 

 with the extinct Sphenophyllales rather than with the Lycopod phylum, though 

 relationship no doubt exists in both directions. 



In the Sphenophyllales and Psiloteae the sporangium-bearing pedicel is to all 

 appearance a ventral lobe of the sporophyll. Yet it presents, in certain cases, the 

 closest agreement with the sporangiophore of the Equisetales, which as a rule 

 appears to represent either the entire sporophyll or an independent outgrowth from 

 the axis. Palceostach/a, indeed, suggests a possible transition from the one type 

 to the other, for here the sporangiophores are inserted immediately above the 

 ' bracts,' almost as in Cheirosti-obus. It is not necessary, however, to strive after 

 a uniform interpretation in all cases. We may regard the sporangiophores either 

 (1) As independent reproductive appendages, which may arise in various positions, 

 or (2) as representing specialised leaves, or portions of leaves, as the case may be. 

 For the latter interpretation analogies may be found among the Ferns. 



6. Notes on the Morphology of the Araucariece. 

 By SiBiLLE O. Ford. 



The Araucarieaj include the two genera Araucaria and Ayathis ; they are 

 characterised by the regularity of their branching and the persistence of their 

 leaves. Small * accessory ' lateral branches may occur in the region of the lateral 

 branches. 



In mature leaves more than one vascular bundle is present with conspicuous 

 transfusion tissue composed of large elements with bordered pits. 



The apex of the stem shows no definite apical cell, but a somewhat irregular 

 dermatogen. Well-marked annual rings may be found in the wood, and bordered 

 pits are found on the tangential walls of the latest formed summer wood. 



Owing to the persistence of the leaves, the leaf-traces are continued through 

 the wood of the stem for some years. Markfeldt has shown that partial tearing 

 of the leaf-trace occurs from about the third year onwards in the region of the 

 stem cambium. In Agathh robusta, however, tearing may also occur simultane- 

 ously in other regions of the trace. 



The roots are diarch or triarch, and secondary thickening ultimately results in 



