﻿146 



REPRODUCTIVE STRUCTURES. 



usually preserved, but in the case of other and younger axes they are sometimes 

 quite complete. The entire series of hairy bracts covers the fruit at the surface of 

 the armor to a depth of from 1 to 2 cm. in the vertical direction to the trunk, to 2 

 or 3 cm. in the lateral and less compressed direction. The diameter of the unex- 

 panded fruit proper is from 3 to 3.5 cm., and its length, as stated, 6 cm., or about 

 the same as that of the peduncle. The outline of the mass of uuexpanded stam- 

 inate fronds, as once-deflexed and closely folded and packed about the ovulate cone, 



is that Of a robust pear ; and Fig. 73.— Cycadeoidea dacotensis. Serial transverse sections, 363, 365- 

 thlS is also, as already seen, 367, from the bispotangiate strobilus (III), T. 214. Enlarged twice. For 



exact position see figure 72. 



that of a well-grown ovulate 

 strobilus of the present, or a 

 very closely allied species, 

 shown in figure 67. That 

 both the staminate and ovu- 

 late forms should succes- 

 sively assume this same out- 

 line served to economize 

 space in the production of 

 fruits within restricted lim- 

 its, tightly wedged in be- 

 tween the old leaf bases of 

 the armor as these were. 



PEDUNCLE. 



The outlines of the 

 peduncle readily appear to 

 view when the serial fig- 

 ures 73 and 75 are examined, 

 the peduncles near the sum- 

 mit of the trunk being, 

 however, less flattened in 

 the vertical direction than 

 those borne lower down. 

 The structure is, as in the 

 case of the ovulate cones 



S3G3 



TZIH. 



S. 363 cuts the upper end of the peduncle (p), the bracts (shown in solid black), and 

 several leaf bases (1). As also indicated by the leaf-base bundles, the arrow shows 

 direction vertical to the trunk which bears the strobilus. 



d O J, S.3CS I -ri'i 



S. 365 cuts the lower portion of the ovulate cone (o), the frond tips (t). and their fused bases 

 forming a continuous disk (d), surrounded by the very numerous bracts; (b) is the bundle 

 ring or cylinder of the cone. See continuation of these figures on next page. 



described, a repetition on a minor scale of that of the trunk, the central woody cyl- 

 inder giving off small bundle traces, which pass out directly to the bracts and 

 staminate fronds instead of to leaf bases. 



BRACTS. 



These are of the same essential structure already described from the ovulate 

 cones of the Bennettites Gibsoniamis and B. Morierei type, though larger and with 

 a very long ramental covering corresponding to their larger size. Although the 

 bract hairs aud general outlines are nearly always clearly indicated, as a rule, the 

 cell structure is not preserved in the several bisporangiate axes thus far studied, 



