Notes . 
181 
of spirally marked cells of the outer cortex.’ The patches were apparently of some 
breadth, but only a tangential section near the surface of the rootlet could show 
clearly the extent and arrangement of these cells. Such a section I have found on 
a slide (prepared by the late Mr. J. Spencer) kindly lent me by Dr. Scott from his 
collection. Its cabinet number is 1527. This slide has two rootlets cut tangentially 
through the outer cortex, and from the better one of the two the accompanying 
drawing has been made with the camera lucida. The rootlet could hardly have been 
cut in a better direction or at a better depth for revealing the details of the vascular 
Fig. 34. 
elements of the cortex. As will be seen from the Fig. 34, they form a complete net- 
work, over a width of six or seven cells, and greatly resemble the termination of the 
vascular bundles in the leaf. Between the spirally thickened cells are found wide thin- 
walled elements from which water could readily pass into the spiral elements and 
thence through the vascular branch into the stele of the rootlet. 
At one or two points where the spiral elements are shown in the drawing in an 
incomplete condition, it is obvious from the difference in focussing that the spiral 
cells were there connected with a vascular branch lying at a different level and not 
in the plane of the section. In the other rootlet seen on the slide there seemed 
to be a slight difference between the cells at the ends of the ramifications and 
the connecting tracheids. The latter were slightly narrower and had a closer spiral 
marking than the former which were of greater width. 
I must express my indebtedness to Dr. Scott, who has placed at my disposal 
this excellent preparation which throws further light on the curious vascular supply 
of the Stigmarian rootlets. 
F. E. WEISS. 
Owens College, Manchester. 
ROOT-PRESSURE IN TREES. — The following observations made upon the 
Wych Elm ( Ulmus Montana) appear to be of some interest. The tree used was over 
thirty feet high, and branched at the base into two main trunks. 
Feb. 20. The larger trunk was sawn across. No bleeding now or sub- 
sequently. 
Mar. 15. The second trunk was ringed, from eight to ten annual rings of wood 
being removed, which formed one half of the alburnum. Flowering 
and foliation in April were hardly at all delayed. 
[Annals of Botany, Vol. XVIII. No. LXIX. January, 1904.] 
