﻿FOLIAGE. 



99 



CYCADEOIDEA COLOSSALIS (TRUNKS 2 AND 10). 



It is of interest to note that the huge branches of C. colossalis Nos. 2 and ioof 

 the Yale collection bear once-pinnate young fronds of the C. ingens and Jenneyana 

 form, though smaller and with apparently fewer pinnules. Especially to be men- 

 tioned is trunk io, which bears, just beneath its large and ^veil-conserved terminal 

 helicoid of ramentum groups, a single partly emergent folded frond, with upward of 

 twenty pinnules in each rank, as seen in the eroded transverse section. The only 

 means of studying this frond would be to first remove it in the form of a cylindrical 

 core, as has been done in the case of various strobili ; and there is every indication 

 that this would be well worth doing. While the bundle system is indicated in the 



Fig. 52. — Cycadeoidea sp. S. 407. X1.36. Transverse section through summit of a trunk, showing numerous 

 erectly prefoliate leaves emerging in a crown. A single older leaf base is seen to the right. The bundle 

 pattern of the rachis outlining a heavy (J is to be noted in three upper left-hand fronds. The more apical 

 helicoidally arranged ramental areas within the crown of emergent fronds may belong to scale leaves or to a 

 succeeding crown of fronds, two, if not three seasons of foliar growth possibly being indicated. 



weathered section by tiny pits marking the position of each bundle of the individual 

 pinnules, there is every likelihood that a centimeter or two beneath the surface of 

 the trunk preservation is more complete, with excellent color differentiation. 



It is an open question as yet whether or not these trunks are not rather to be 

 referred to C. dacotensis; but in either case it is equally satisfactory to know that 

 there is at haud a series of trunks illustrating the foliage of the great branching 

 forms, and clumps of trunks shown on plates v-xm, although time has not as yet 

 sufficed for more thau an initial study of all this material. 



Fortunately, as may here be added, the material now in the several musems of 

 this country will in the end be found to permit the determination of the prefolia- 



