﻿148 REPRODUCTIVE STRUCTURES. 



normal length where the scales snrronnd the lowermost normal-sized ovules. It is 

 also noteworthy that these basal interseminal scales are largely composed of reticu- 

 late to scalariform tracheids, much as in the older ovulate cones of the very differ- 

 ent species C. Wielandi. The length ot the sporophylls and interseminal scales 

 covering all the lateral surface of the cone between the basal seed-bearing region and 

 apical-scale region — that is to say, over a lateral zone with a height of 25 mm. — 

 is about 1.5 mm. and markedly uniform. It may be said that on a free and une- 

 roded surface of one of these cones, precisely the same characteristic pattern as in 

 other and larger ovulate cones would be found present. And, indeed, it is of much 

 interest to observe that were there any especial need for a preparation showing these 

 features, one could be readily made, because of the fact that between the decurved 

 tips of the stamiuate fronds and the lateral surface of the cone there is usually a 

 layer of clear silica fully 0.5 mm. in thickness, as may be noted in plates xxxv 

 and xxxvi, photograph 2. Since the tips of the minute interseminal scales and 

 the young micropylar tubes project into this clear silica but not nearly through it, 

 it must be perfectly feasible to saw and polish down nearly to the outer surface of 

 the cone and thus isolate absolutely perfect and uneroded examples. As some of 

 the cones have a clear and resinous rather than a dark surface, every feature of sur- 

 face sculpturing must stand out with absolute clearness in such a preparation ; for 

 even in the case of transverse sections the band of clear silica permits one to see 

 somewhat beneath the surface, and get a glimpse of what would be clearly shown by 

 an isolated cone. (In the case of older ovulate cones there is often so much apical 

 fracture, or, together with basal fluting, such a close appression of hairy bracts, that 

 a sharply delimited surface and perfect result like that just described could but 

 rarely be secured.) 



The ground tissue of the elongate and conical termination of the peduncle or 

 "cushion" of the ovulate cone, or, more properly, the receptacle which bears the 

 zone of seed stems, is not well preserved, although the general structural features 

 are clearly indicated. There is first a central regularly disposed system of anastomos- 

 ing gum ducts, and, secondly, the main conductive system, indicated by strands of 

 well-preserved xylem, which extend in cylindrical order throughout the length of 

 the cone and thus form a continuation of the woody cylinder of the peduncle. 

 In these strands or bundles, however, the xylem elements are not radially arranged. 

 The cylindrically disposed bundles as they take their course throughout the length 

 of the cone send out towards the bases of the seed stems and interseminal scales 

 great numbers of smaller traces, doubtless regularly arranged. The number of 

 cells in each larger strand of the main bundle cylinder as cut transversely is twenty, 

 more or less (see fig. 80 a). In longitudinal sections the strands are seen to consist 

 almost entirely of scalariform cells, with some spiral forms, being structurally simi- 

 lar to the bundles from the corresponding portion of an ovulate cone shown in 

 figure 80 b. Just exactly what phloem cells were present is not clear, although 

 there are some slight indications in the way of coloration and texture which indi- 

 cate a main phloem mass distal to xylem. But whatever ma)- have been the extent 

 of phloem development, it is to be noted that in the examples before us there was 



