﻿I I 2 



REPRODUCTIVE STRUCTURES. 



the fruit is the husk of hair-covered bracts, several layers deep, and beyond these 

 the leaf bases. 



In the most favorably cut median longitudinal sections — that is, iu those cut 

 radially and longitudinally to the parent trunk and carefully oriented with respect 

 to the axis of the fruit itself, as iu that shown in text-figure 59 aud in photo- 

 graph 4, plate xxiv — the relation and form of the several parts become wholly clear. 

 Various of the seeds making up the seed layer are seen to be cut more or less tan- 

 gentially aud a few mesially from the seed base to the summit of the micropylar 

 tube, while the individual seed stems and the interseminal scales or sterile pedicels 

 may each be traced to their insertion on the convex "cushion" or receptacle beneath. 

 Exteriorly in such sections the bracts are usually quite evenly cut lengthwise from 

 base to summit, as in section 391 {cf. figs. 56 and 59). Likewise, the insertion of 

 the peduncle on the cortex axillary to a leaf base is clearly to be seen, as well as 



Fig. 58. — Cycadeoidea Wielandi. T. 393. S. 393. X 2. Transverse section through 

 armor, cutting two adjacent ovulate strobili and their surrounding bracts and leaf bases. 

 The section passes through the seed pedicels beneath the lowermost seeds and not 

 far above the insertion of the pedicels on the parenchymatous receptacle. 



Leaf bases stippled, bracts and pedicels in solid black, with the space occupied by the surrounding 

 interseminal scales left blank, except the outer row of tips marking the surface of the cone. It is of 

 especial interest that the cone to the left bears relatively few seed pedicels, many interseminal 

 scales occupying all of the left outer portion of the cone. 



the cortical bundle traces, which in some instances may be traced to their origin on 

 the xylem zone of the trunk. All these features appear with diagrammatic clearness 

 in section 392, figure 59, and in the photograph of the same (plate xxiv, No. 4). 



Having now given, both on the basis of external examination alone and thin 

 sections, the disposition of the several organs of the ovulate fruit, detailed descrip- 

 tion based on various cones borne by trunks 77 and 393 may best be taken up in 

 the following order: Peduncles; bracts; interseminal scales ; seed pedicels ; seeds; 

 embryos ; pre-embryonal structures. 



