by two branchlets lining the edges of a long aperture in the shell. The two branches (d) and (e) form an intermingled head of dense healthy foliage, twenty-four feet in height, as measured accurately with a rod. Farther, the trunk gives off at its very base a vigorous leafy young branch (g), which, travelling along the ground at the west wall, without rooting anywhere, fills the whole space with what appears on cursory examination to be a crowded plot of young yew plants. This branch bore yew berries last autumn. The convex side of A also gives off several small upright healthy branchlets; which, however, do not rise so high as to mingle their foliage with that of the two principal branches.

B [Pl. XIII. No. 4] arises from a portion of old trunk, two feet eight across at the ground; and in the form of a very irregular hollow shell of wood from two to three feet in width, covered with bark next the wall, slants slightly upwards to a distance of nine feet, where it is supported by a stone-pedestal. It is composed exactly as the shell of A; and, except close to the ground at its origin, it is everywhere sound, hard wood, fit for ornamental work, even where it is on the inside grey and apparently decayed. It gives three considerable branches, one above the root, another which rests on the pedestal, and a third midway between these two. The first is 34 inches in girth, the next 51, and each division of the terminal one 19. They are upright, or nearly so, and bear a mingled low head of dense healthy foliage. It will be seen presently that these branches must be of considerable age. This portion of the tree appears to have belonged to one of its great branches; which, decaying with the part of the trunk supporting it, had gradually bent down into its present position. The dead mass k, connected with A, probably belonged to another similar branch.

D is a root-stump, visible only on scraping off a very thin covering of soil. It is then seen to be sound wood, of the usual mingled red and yellow colours of yew-wood. The existence of this stump led me to hope that an under-ground continuation might connect it with A. Mr Campbell endeavoured, at my request, to settle that point by trenching the intervening ground, and subsequently repeated the digging in my presence. But he found no connection with

A,-only rootlets of D, and about 16 inches under the surface minute fragments of rotten wood, which Mr Sadler ascertained to possess the microscopic characters of yewwood. Mr Campbell however apprized me that graves had been several times dug in the enclosure, and on several of these occasions large masses of wood had been thrown out; and afterwards the church beadle, a vigorous man of seventyeight, informed me that he recollected when D was almost joined to A by a mass of wood, which was removed by a former proprietor for ornamental work, and that a grave had been dug since in the interval thus left. Hence our failure was inconclusive, and it also became superfluous to carry through our intention to trench other parts of the inclosure.

C, a young tree outside the churchyard wall, but almost touching it, is about twenty-eight feet from the nearest part of the old trunk. It is usually spoken of as the product of a shoot froin the root of the old tree. I am not aware that the yew is prone to throw up suckers from its distant root-branches; certainly there is no other similar plant, young or old in the immediate neighbourhood of the yew at Fortingall; and nowhere has the trailing young branch (a) rooted. But there is within another inclosure, thirty yards from the nearest part of the old trunk, another very young yew which arose spontaneously, and must have sprung from a seed. Such in all likelihood was also the origin of C. I call C young, but only by comparison; for it must be at least 150 years old. It is a handsome thriving tree, with a cylindrical trunk, somewhat grooved, 53 inches in girth at five feet from the ground, branching at eight feet, and bearing a fine leafy head, pointed and altogether like the pines in form, and thirty-five feet in height by two independent measurements with Atkinson's hypsometer.

Such being the facts, so far as now ascertainable, what light do they throw upon the age of the Fortingall yew?

Taking up again the essential question,-whether there has been one tree or more than one,—it is obvious from the ground plan, and the sketch of A, that, were there no other materials for decision but what may be now seen, A would be pronounced to have constituted of itself a tree about eight feet in diameter. For the large mass from (d) to (e) and

the separate portion (a) leave little for the imagination to fill up, in order to complete the circle of an original trunkbase. Then, instead of showing any relationship in position or otherwise to B, A has turned its back, as it were, on that mass of old trunk; so that former unity might seem impossible. But on the other hand, if A be supposed to be singly the ancient tree, not only will it not account for even half the girth assigned to it by Pennant as well as Barrington; but likewise there is no gap by which a boy,--and much less a funeral, could pass through. It would be illogical however to discard, on the ground of present appearances, the independent testimony of a naturalist and a barrister, who separately examined the tree 110 years ago, when it existed in a less dilapidated state;—supported too, as that testimony is, by the independent recollections of Captain Campbell in 1769, of Mr Macdonald's old parishioner in 1806, and the present beadle of Fortingall. This proposition is irresistible, if the present apparently incompatible condition of the remains is capable of explanation from the known influence of natural causes. Now, the tree itself supplies such an explanation. The hollow trunks of old decaying trees undergo strange metamorphoses by fresh growths within them; and this observation is peculiarly applicable to the

yew.

Mr Bowman in his paper on the longevity of the yew ["Mag. of Nat. Hist." 1837] has described and figured a tree whose state may serve to clear up the case of that at Fortingall. In the churchyard of Mamhilad near Pontypool there was in 1837 an ancient yew, twenty-nine feet and a half in girth at two feet and a half from the ground, hollowed out by age, and presenting in its circumference a considerable gap, through which was seen at the opposite side the trunk of a vigorous younger tree, several feet however in diameter, united to the shell behind, and also by two branches above. Mr Bowman suggests that, when the shell should fall away through gradual decay and disappear, the younger tree would take its place, and nothing would remain of the old one to indicate its history. But if only one side of the shell were to disappear in the first instance, the remains would have a crescentic shape, with such a curling inward of the horns of the crescent, as would

appear to assign to the original trunk a totally different form, and a girth altogether different from its original condition. A process very similar is now going on in the Fortingall yew. A young growth, completely covered with bark (d) has sprung up within the shell of the trunk, and is united with the trunk-shell behind it, and by two branches with the branch-shell above. When that portion of the shell beyond it towards (a) shall disappear, and also (a) itself, the young growth would form the limit of the trunk in that direction, and greatly alter what we at present know to be the form and dimensions of this part of the remains of the tree. Farther, there is no great assumption in supposing that had been formed, as it now stands, in the very same way,—the shell, originally extending outside of it, having since disappeared.

On the whole then the present apparently inconsistent condition of the ruins of the tree may be reconciled with the old descriptions. It is a matter of regret that these descriptions were not more precise, and especially that no ground-plan of the trunk has been given before the present occasion. All remaining uncertainty as to the original form of the Fortingall yew would thus have been removed.

Little information as to its rate of growth is to be got from sections of the Fortingall yew itself. The only available parts remaining are the outermost portions of the old trunk, representing its growth probably long after it had become a shell, and consequently impaired in vitality,—or the branches, in which in all trees the annual rings of wood, for the same periods of time, are much narrower than in the trunk. In all parts of the tree which I have examined the rings are very fine, so fine in general as not to be counted without the aid of a lens. On a six-inch transverse section of the outside of the shell B, amidst numerous fine and much contorted rings, I found one narrow line on which for nearly two inches the rate was so much as an inch in 27 years, and on another small section I found for 1.13 inch a rate of one in 35 years. But on many parts of the shell A, and the branch K, the rates varied from one inch in 48 years to one in 66, 68, 70, and 90 years; and at the base of the second branch of the shell B a roundish section, represented in Pl. XIII. No. 4, and indicating amputation by

some depredator, shows 137 rings on its longest radius of two inches and a half; that is a rate of an inch in 50 years for the stolen branchlet. None of these rates however could be reasonably taken as denoting the growth of the trunk for much more than its last hundred years of life.

It is better to use the general rules formerly arrived at, according to which the tree in the first place may be assumed to have attained a girth of 22 feet in a thousand years. After that age no information yet got warrants a rate of more than an inch in 35 years. Taking the lowest measurement of Barrington at 52 feet, the difference will thus add 2000 years to the age of the Fortingall yew, making it in all 3000 years old when measured in 1768-9. The result is startling, but not so improbable as may at first be thought, if it be considered that several English yews of scarcely half the girth are not without good reason held to surpass materially a thousand years of age, yet still appear to be in vigorous health and steadily increasing; and that upwards of 3000 rings have been actually counted on the stump surface of a Californian Sequoia.

V. Remarks on some Species of Rheum cultivated in the Edinburgh Royal Botanic Garden. By Dr J. H. BALFOUR, Director. (Plate XIV.)

(Read 10th July 1879.)

Sir Robert Christison, at the meeting in June (pp. 403410), alluded to the Rheum palmatum, Linn., which has been grown in the Garden since the days of Dr John Hope, Professor of Botany in the University of Edinburgh, and which this year has sent up flowering stems and produced fruit. The seeds seem perfect, and we hope that they will germinate. Another plant of Northern Asia, allied to R. palmatum, and considered as a variety of it, is R. tanguticum, Max. (Plate XIV.) This plant is referred to in the Proceedings of the Society, vol. xiii. p. 21. It was sent to the Garden by M. Regel of St Petersburgh in 1877, and it has flowered and produced fruit this season.

Its leaves are similar to those of R. palmatum; its flower2 F

TRANS. BOT. SOC. VOL. XIII.