114 REPORT—1850. 
calls epiblema. In certain instances this external layer of cells seemed capable of 
developing appendicular organs, as was the case with plants growing in the air. The 
author had previously published a description of certain bodies which occurred on the 
surface of the stem and leaves of Callitriche verna. ‘These bodies were stellate in form, 
and consisted of several cells attached to one which acted as the base and attached 
the rest tothe surface. Since that time he had observed the same bodies covering 
the surface of the stem of Hippuris vulgaris. They were composed of a larger number 
of cells in Hippuris, and the author had not detected them on the leaves. Finding 
them on Hippuris and Callitriche, he had sought them on Myriophyllum, but had not 
succeeded in detecting them there. He had however detected similar bodies on the 
surface of the leaves of Pinguicula vulgaris. These had been previously described 
by Professor Dickie. In Pinguicula the stellate bodies were found lying directly on 
the surface of the leaf, or elevated upon one, two, or more cells, so as to resemble 
clavate hairs. In Pinguicula they were quite distinct from the stomates, and this 
might be taken as an indication of the nature of these bodies in Callitriche and Hip- 
puris. The author had also observed bodies of a similar kind on the surface of the 
leaves and on the so-called hairs of Drosera rotundifolia. It was an old observation 
alluded to by Meyen and dwelt upon by Morren, that the hairs of Drosera contained 
spiral vessels. The author had traced these to the bundles of vessels which formed 
the veins of the leaf, and stated, that we must regard the hairs of Drosera as segments 
of the leaf. He regarded as the true hairs of Drosera, the stellate bodies above 
referred to, 
A few Remarks on the Treatment and Flowering of a Plant of Dracena 
Draco, or Gum-Dragon Tree, in the Botanic Garden of Trinity College, 
Dublin. By J.T. Mackay, LL.D., M.R.LA., Director. 
The Dracena Draco, or Gum- Dragon Tree, on a plant of which I beg leave to make 
a few observations, was raised by me in the College Botanic Garden in 1810, along 
with several others from seeds brought from Madeira. After it had been grown in 
a pot for ten years, it was planted out into a bed of earth in a large stove or hot- 
house. About three years ago it became too tall for the house ; and in order still to 
secure the plant for the collection, the following experiment, suggested by my intel- 
ligent chief-assistant Mr. Bain, was made by him :—The stem, which was then about 
eighteen feet high and fifteen inches in diameter, was during six months gradually cut 
across four feet above the root, about an inch deep at a time, when a little hot lime 
was applied to the wound to prevent bleeding. The root and lower portion of the 
stem were then removed’as being useless, and the upper portion of the stem suspended 
immediately above the former station of the plant. In the course of eight months, 
during which time it was kept perfectly dry, it threw out several aérial roots from the 
edge of the stem where it had been cut. It was then lowered into its former position, 
and had the stem and roots sunk about four feet in dry sandy mould. This was done 
a year and a half ago; and the plant, which is now in excellent health, has lately 
flowered, and is, I believe, the only one that has done so in Great Britain or Ireland. 
It is a liliaceous plant, having numerous small flowers produced on racemes, com- 
posing the large panicle, which was four feet in length and three feet in diameter. 
A portion of the panicle and two drawings of the plant I now lay before the 
meeting. As the above experiment on Dracena Draco has succeeded so well, the 
author thought the same treatment would be well worth trying on palms and other 
endogenous plants, when they become too tall for the house. 
On the Effects of Salt on Vegetation. 
By Dr. Aue. Vortcxer, Prof: of Chemistry, Roy. Agricul. Coll. Cirencester. 
This paper contained the preliminary resulfs of some experiments undertaken with 
“a view of studying the effects of salt on vegetation in general, and to determine more 
in particular in what quantity salt produces a beneficial. and in what quantity an 
injurious effect on different plants. The plants selected for experiments were cab- 
bages, beans, onions, lentils, Stellaria media, Senecio vulgaris, Carduus pratensis, , 
Γ' 
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