Further Notes on Floral Structures. 91 



Weltrichia, as an early member of the William soman tribe, 

 of which the habitus is now so fortunately known, Cycadeoidea, 

 and Wielandiella thus stand in reciprocal relationship. The 

 first is simple, primitive, cycadean, but fairly started on the 

 course of change leading towards angiospermous floral types. 

 The second has by reason of silicification added most to our 

 knowledge, but its xerophytic, stereotyped features have long 

 obscured our conception of how truly generalized the cycado- 

 phytans really are in stem leaf and fruit. While the third with 

 its slender freely dichotomized branches and laminar leaves, in 

 reality but little removed from any pinnately net-veined type, 

 has all but completed the process of microsporophyll reduction. 



More or less in contrast to this staminate reduction, the com- 

 plexly organized Cycadophytan seeds are uniformly ancient of 

 type. In their coats are best seen Cycadofilicalean or Pterido- 

 spermous features that add not a little in gaining ideas of race 

 relationship ; although at the same time both style and stig- 

 matic surface begin to appear as structures of secondary origin 

 and function. It is in the seeds that but recently the distinct 

 resemblances to Gnetum have been noted that may go to indi- 

 cate this as some long persistent non-plastic form that origi- 

 nated when the great races preceding the Angiosperms began 

 to convert Paleozoic structures to Mesozoic needs. 



And similarly the hiatus between flower and inflorescence, 

 once held all but impassable, may be but slight if Tumboa 

 proves to be another such a laterally related but even older and 

 more stereotyped line ; it being quite conceivable that con- 

 tinued reduction of lateral branches bearing, like those of 

 Cycadeoidea, flowers derived from strobilar crowns, could 

 finally give rise to Tumboan and other types of inflorescence. 



