Notes. 
47i 
there are three cells, and mostly more than one ovule in each cell, though each nut is 
usually only one-seeded. The ovary of Juliania and of Orthopterygium invariably 
contains only one ovule. The flowers and nuts of Castanea are collateral, as in 
Juliania. The seeds of both orders are exalbuminous, and the cotyledons are 
epigaeous in germination. 
Weighing the characters in which there is agreement or similarity between the 
Julianiaceae and the Anacardiaceae, and those in which there is agreement or 
similarity between the Julianiaceae and the Cupuliferae, the latter in my estimation 
preponderate ; and I cannot suggest a more natural position for the Julianiaceae, in 
a linear arrangement, than between the Juglandaceae and the Cupuliferae. 
W. BOTTING HEMSLEY. 
Herbarium, Royal Botanic Gardens, Kew. 
ON THE SEEDLING STRUCTURE OF GYMNOSPERMS \ Taxus haccata. 
— The two cotyledons each contain a single collateral bundle, which is, in some 
cases, slightly mesarch. A section of the axis, taken through the cotyledonary 
node, shows the central region to be occupied by six plumular bundles arranged in 
two groups. Each seed-leaf-trace, at its entry into the hypocotyl, has its xylem 
arranged in a V-like manner, the protoxylem being near the apex, which is pointed 
outwards. Each cotyledonary bundle travels obliquely downwards, and during its 
passage the phloem is resolved into two parts. At the same time the metaxylem 
passes in more quickly than the protoxylem, so that the latter, for a time, is entirely 
mesarch in position. The phloem masses of the cotyledon bundle fuse with the 
corresponding tissue of the nearest plumular bundle — the three strands of each group 
having fused together— and, concurrently, the metaxylem of the same traces moves 
towards the xylem of the epicotyledonary bundles ; hence the protoxylems of the seed- 
leaves are left in a more exarch position, and, ultimately, are quite exposed. The 
vascular tissues close up and become more compact, thus a typical diarch root results. 
It is not possible to distinguish any rotation of the protoxylem : it ultimately occupies 
an exarch position, because it is left isolated by the movements of the metaxylem. 
There may be made out, however, an indefinite rearrangement of the protoxylem, 
coupled with a slight centrifugal movement, after the exarch position has been 
attained. 
Taxus cuspidata , as far as can be ascertained from the study of old seedlings, 
does not differ in any essential feature from the above species. 
Cephalotaxus pedunculata is very similar to Taxus. The main points of difference 
are as follows : ( a ) The single bundle of each cotyledon shows the mesarch structure 
more highly developed; and (h) the seed-leaf-traces do not bifurcate so soon. They 
enter the central region of the axis as well-defined collateral endarch structures, and 
form a cylinder with the plumular traces, the phloem forming a practically closed 
1 Abstract of paper read before Section K at the York meeting of the British Association, 
August, 1906. 
