G. R. Wieland — Cycadeoidean Flower-bud Structure. 123 



indicates that considerable further structural details may yet 

 be observed, and thus later permit accurate specific determina- 

 tion. For the present, however, that which mainly concerns 

 us is the plan of the flower and its outer form, both being 

 clearly exhibited and quite accurately determined. 



The first or trial section cut from the isolated bud was that 

 drawn in figure 1. It clearly shows the characteristic small 

 size and lozenge-shaped transverse section of the nearest adja- 

 cent leaf base well crowded to the side by the series of rela- 

 tively very large bracts. The outer bracts appear the larger 

 because cut at a much higher level than those next the essen- 

 tial organs, the bracts being slender near their insertion and 

 increasing in size toward and beyond their mid-length. 'As 

 they are still large where truncated by the eroded outer surface 

 of the fossil, about a centimeter above the level of the trial sec- 

 tion, the actual terminations as in most fair-sized fruits cannot 

 be observed. It is nevertheless clear enough that the bracts 

 were long and heavy, and formed a dense protecting husk pro- 

 jecting well above the extreme apex of the flower proper. At 

 the center of the bract series, as one notes in figure 1, only the 

 disk features may be seen since the section is cut well above 

 the apex of the ovulate cone, and also passes above the highest 

 of the synangia. All the tissues cut at this level, which was 

 intended to and actually does traverse the broadest part of the 

 flower bud, are therefore rachidal. And furthermore, as one 

 attentively studies the section it is plainly seen that the closely 

 appressed and transversely cut rachides have the appearance 

 of a series of heavy Y's with their sides close together and 

 their vertices outlining a very small circle or point near the 

 center of the flower, except that in several instances the arms 

 of the V's barely touch at the center, while in one case the Y 

 section of a rachis is seen to unite near the inner or vertical 

 point with the arm of the adjoining rachis, the other arm of 

 which is thus left entirely free. But at the center be it noted 

 that there is not the least trace of the decurved tips of fronds 

 clearly observable in the longitudinal and. more basal transverse 

 sections, so that there can be no mistaking the fact that this 

 entire section shows only the development of the heavy 

 rachides. Obviously enough, therefore, the series of sector-like 

 rachidal sections pairing into, as one may readily count, ten 

 Y's with arms mostly joined but sometimes free, or again fused 

 with an adjacent member, indicates one of two possibilities. 

 Either the disk divides irregularly into outer or ventral wing- 

 like expansions of the rachides, the number of which would in 

 this case be somewhat uncertain, or it divides at quite exactly 

 the level of this section into ten distinct rachides, each of 

 which is deeply incised by a median ventral furrow so as to 





