691 
Seedling Structure of Gy mno sperms. I. 
elements, however, are not very numerous. This feature has already been 
described by Worsdell , 1 and, to save reiteration, it may here be remarked 
that Worsdell describes the occurrence of mesarch structure in Taxus , 
Ginkgo , and other plants, and the presence of transfusion tracheides in 
Cephalotax'iis , Taxus , Sequoia gig ante a, Widdringtonia Whytei, Libocedrus 
decurrens , &c. 
Diagram i. Cephalotaxus. In this, and in all the following text-figures, the protoxylem is 
indicated by the black areas, the metaxylem by dots, and the phloem by diagonal shading. 
Transition. At the cotyledonary node the bundles retain their undi- 
vided nature and gradually pass inwards towards the central region of 
the hypocotyl, during which passage the centripetal wood dies out. The 
arrangement of the vascular bundles at the top of the hypocotyl is, roughly, 
elliptical ; the two seed-leaf-traces occupy the foci of, the ellipse, and there 
are two groups of plumular strands, three in each group, placed at right 
angles to the cotyledonary plane (Diag. 1, Fig. 1). On tracing the bundles 
downwards, they undergo a centripetal displacement, so that they soon 
form a continuous vascular ring by the coalescence of the phloem-masses 
( Diag. 1, Fig. 2). 
The abundant protoxylem of the cotyledonary bundles still occupies an 
1 Worsdell. : On Transfusion Tissue : its Origin and Function in the Leaves of Gymnospermous 
Plants (Trans. Linn. Soc. London, 2nd ser. , vol. v). 
3 A 3 
