586 Davey. — Seedling Anatomy of certain Amentiferae. 
related to central and lateral cotyledonary traces as in Juglans cinerea. 
The material available was so old that secondary thickening in the region 
of the cotyledonary node prevented the primary structure of the plumular 
traces from being followed with certainty. 
The genus Juglans is interesting, since in some species there is com- 
plete continuity of a vascular unit similarly constituted throughout root, 
hypocotyl, and epicotyl. In all the species there is great similarity in the 
structure of the hypocotyledonary stele. 
The seeds and seedlings of the genus Carya are not so large as those of 
the species of Juglans described above, but in habit and mode of germina- 
tion they are similar. 
Carya olivaeformis. This seedling is smaller and slenderer than that 
of the other species described. The hypocotyl possesses eight proto- 
xylem centres surrounded by the customary tangential metaxylem and 
diverging phloem groups. Passing upwards, six of the xylem poles, four 
diagonal and two cotyledonary, are continuous with the xylem of the 
central and lateral cotyledon traces respectively. The two remaining 
intercotyledonary strands with their related phloems extend up into the 
epicotyl, forming the traces of the first two plumular leaves exactly as 
in Juglans nigra. 
In young seedlings octarchy persists throughout the root, but in one 
somewhat older individual the intercotyledonary poles diminished in size 
and became merged with one of the neighbouring diagonal ones by 
suppression of the intervening phloem group. The cotyledonary poles 
became less well developed, and were represented at low levels by tangen- 
tial arcs of xylem. Rootlets arose in connexion with the diagonal poles 
only. 
This seedling shows the combination of diagonal and cruciform tetrarchy, 
and is further interesting in that it possesses well-developed intercotyle- 
donary root poles organized in connexion with plumular leaf-traces as 
in Juglans nigra. 
Caiya amara. The only seedling obtained was very old and had pro- 
duced great length of root with much secondary thickening, although the 
plumule had not emerged from the seed. 
In the hexarch root two of the poles are in the cotyledonary plane, 
while the remaining four are diagonal. The poles persist in the hypo- 
cotyl and are connected with the central and two lateral double bundles in 
the cotyledon bases. Higher in the cotyledon petiole there are six bundles 
arranged in pairs, each being surrounded by a single layered sheath of cells. 
A thick-walled tannin containing endodermis surrounds the stele in both 
root and hypocotyl. At the cotyledonary node portions of it pass out with 
the cotyledon traces and are continuous with the bundle sheath in the 
petioles. 
