136 G. R. Wieland — Oycadeoidean Flower-hud Structure. 



ing that if the Cycas carpels bear any relation to Angiosperm- 

 ous carpels, then Cycas, despite its seemingly ancient form, is 

 not the least but must be the most specialized member of the 

 Cycadacew. Similarly the quadrate group of seeds in Genetop- 

 sis would be intermediate between a " flower " and a " cone." 

 While in the sense here perhaps rather dimly glimpsed, all 

 cones of present day gymnosperms are at least once compound 

 axes, and the conception of the ovulate strobilus of Gycadeoidea, 

 as a compound axis with interseminal scales analogous to 

 bracts, so insistently held by Lignier, may possibly prove to 

 more nearly express the truth than my own view that the stro- 

 bilus is simple, the interseminal scales resulting directly from 

 sporophyll sterilization. In either case the Cycadeoidea seed 

 pedicel is a far more ancient structure than any of the modern 

 carpellary leaves of cycads, which is the more important point. 

 But however these structures be viewed, the thought comes to 

 mind that no closing words of my own can be quite so helpful 

 or explanatory as an opinion of Thiselton-Dyer, which I again 



quote : " an ovule is a sporangial structure 



and it is not easy to see anything in a pinna which is directly 

 comparable to it. Morphological conceptions must not enslave 

 us, and I see no reason why sporangial structures, like buds, 

 may not appear anywhere." 



