Page:Hardwicke's Science-Gossip - Volume 1.pdf/290

ting the mistletoe; and that by seeds alone does the plant take entire possession of the tree. During last winter I examined some scores of trees of different kinds, chiefly apple, poplar, and thorn, and found seeds deposited on them in large numbers and large masses by birds. In the notes to an

edition of Evelyn's Sylva by Dr. A. Hunter, 1776, I find:—"It is the opinion of some that it is propagated by the Misleto-Thrush, which, feeding upon the berries, leaves the seeds with its dung upon the branches of the respective trees where the plant is commonly found. Others say, that as the berries are extremely glutinous, the seeds frequently stick to the beaks of those birds, which being rubbed off upon the branches of trees, they become inoculated, as it were, and take root. In the same manner the Misleto may be propagated by art; for if the berries, when fully ripe, be rubbed off upon the smooth part of the bark of almost any tree, they will adhere closely, and produce plants the following winter." Adopting the suggestion expressed by Dr. Hunter, I see no difficulty in the fact that the plant is found on the under side of a bough. Or again; we all know that water running on the surface of a cylindrical body does not fall off from side, but by attraction follows the surface, unless diverted, to the middle of the under surface. Might not the rain thus gradually carry down, or leave in an intermediate position, the seeds deposited by a bird? The viscid matter enveloping the seed would still be adhesive enough to keep the seed attached to the bough. As an instance of this viscidity, on December 23rd last, I found a mass of seeds deposited by a bird on a painted gate-post. After all the storms of rain and snow and the severe frosts which we had during January and the beginning of February, the mass was there still, and showed no sign of falling from the painted surface of the post. The seeds, after having been deposited, have a great enemy in the Great Tit, and very probably in other birds too. On one occasion I climbed a tree covered with Mistletoe, and found numbers of seeds rifled, leaving the mere integument. Five minutes' watching showed a Great Tit at work upon a mass on another tree.

I have not yet found a large per-centage of plants on the under side of the branches, but on the contrary have found them on the upper side or edge.

No matter in what position the seed is sown, the same plane of growth continues throughout, and the plant does not bend upwards, as plants generally do.

The old moss and lichen-covered trunks of apple-trees I have, last winter, seen covered with such clusters of young plants as one would expect to find from the successful germination of masses of seeds like those I have noticed deposited on all parts of trunks.

It may be asked:—"Why is not the Mistletoe more widely spread, if birds carry the seeds?" This is easily answered by the facts; first, that the plants are diœcious, and therefore the chances are numerous against the seed possessing the principle of life. The majority of plants in an orchard of several acres

which I examined were pistiliferous. Out of fifteen trees which I specially examined, twelve bore only pistiliferous, two both pistiliferous and staminiferous, and one staminiferous plants only. Secondly, many seeds will be annually destroyed by such birds as the Tits.

The seed being deposited, no matter in what position with regard to the bough, the radicles are directed to the bark, and the root penetrates to the hear of the wood. I have cut specimens having the plants growing in every possible direction, and yet a section vertical to the plane of growth of the bough on which it is found, always exhibits the root forcing its way to the heart of the wood or beyond the heart, at right angles to a tangent drawn from the point of contact