100 



HARDWICKE'S SCIENCE-GOSSIP. 



potatoes Lave beeu taken should be carefully ex- 

 amined. It is not improbable that the winter life 

 of the fungus may reside in extremely fine com- 

 pacted threads under ground, and near the decaying 

 tubers. Mr. Smith thinks De Bary's statement 

 that there is nothing in one potato plant more than 

 in another to predispose it to the attack of the 

 disease, is " not proven." The forthcoming great 

 trial of potatoes by the Royal Agricultural Society 

 will probably set this important question at rest. 



Mr. Worthington Smith has himself recently 

 made some experiments on samples of different 

 potatoes, in all stages of disease. These he re- 

 counts in the above article, and we would strongly 

 recommend its perusal to all interested in the ques- 

 tion. One of the varieties that appears to have best 

 stood the experiments exposing it to the attacks of 

 the disease, is that recently brought out under the 

 name of the "Red-skin Flour-ball." "Paterson's 

 Victoria" seems to have been another good sort, 

 whilst "Flukes" suffered badly, as also did the 

 kinds known as "Peach," "King of Earlies," 

 "Early Rose," " Kentish Early," and others. The 

 potato-skins resist decomposition to the last. The 

 author (like Prof. Dyer, in an article in Science 

 Gossip for 1872) is of opinion that the most reason- 

 able suggestion for exterminating the potato disease 

 is to cultivate those early varieties which mature 

 their fruit before the fungus makes its attack, and 

 so to evade the disease. And yet it was a positively 

 late potato, and not an early one, which, according 

 to Mr. Smith's experiments, best warded off the 

 murrain. So surrounded with difficulty is this most 

 important inquiry. 



OLD YEW-TREES AND THEIR PRE- 

 SUMED AGE. 



TN remarking upon "Ancient Trees" in Science- 

 -■- Gossip (No. Ill, page 50), E. Edwards has 

 given some particulars as to remarkable yew-trees, 

 which are very interesting, but the alleged age of 

 some of the trees mentioned seems mere supposition, 

 founded on no accurate or proximate principle. 

 What data is there for saying positively that the 

 Gresford Yew was planted in the year 426 ? If we 

 compare its dimensions with the Fortingal Yew 

 (56^ feet in girth, and in a ruined state), which is 

 the only British yew that can be certainly referred 

 to Roman times, it is scarcely conceivable that the 

 Gresford Yew can be dated so far back. The yew 

 represented in the wood-cut that illustrates the 

 article referred to, is assuredly not the " Eortingal 

 Yew," as stated, for it differs materially from the 

 representation in Strutt's " Sylva," and copied on 

 a smaller scale in Loudon's "Arboretum Britanui- 

 cum." There are many yews in existence as large 

 in dimensions as the Gresford (Denbighsliire) Yew, 



and some of greater magnitude. If the Tisbury 

 Yew, in Dorsetshire (the notice of which E. 

 Edwards has taken from Lauder's edition of " Gil- 

 pin's Forest Scenery "), is " now standing," it must 

 be the largest in England ; and the Crowhurst Yew, 

 on the borders of Kent and Surrey, is almost the 

 only one still floui-ishing, which, though hollow, can 

 compete with it for'magnitude. Of this latter tree, 

 it is stated in the Illustrated News, which a few 

 years ago gave a view of it, that "the interior 

 is hollow, and has been fitted up with a table in 

 the centre, and benches around for as many as 

 sixteen persons." One of the most massive and 

 yet hollow yews that I know exists in Marden 

 Churchyard, Herefordshire, having a seat around 

 its interior where I have reclined, and ten or twelve 

 persons might have joined me, sitting rather close. 

 This yew measures 30 feet in girth. In Mamhilad 

 Churchyard, Monmouthshire, there are thirteen 

 fine yews, the largest of which measures 29 feet 

 4 inches in girth, and has within its hollow a sepa- 

 rate bole, which has originated by a process of 

 natural inarching, and, as Loudon intimates, may 

 exist a thousand or more years hence, when the 

 original tree of which it was a scion has yielded to 

 decay or the tempest's rage. 



Professor de CandoUe, from an examination of 

 various yews, young and old, arrived at the con- 

 clusion that in very old trees the average of their 

 increase in size would be a line annually, so that 

 the lines of their diameter would correspond with 

 their age. On this principle, the Tisbury Yew would 

 be more than 1,780 years old, and the Fortingal 

 Yew, reckoning its girth at 57 feet, would have 

 existed 2,736 years, and as Dr. Neill, who visited 

 the tree in 1833, suggests, " was a flourishing tree 

 at the commencement of the Christian era." Pro- 

 fessor Henslow and other botanists have, however, 

 thought that the measure of De Candolle made yews 

 too old, and they would certainly increase in size 

 more rapidly for the first three hundred years, as I 

 have observed in some felled yews that came under 

 my own notice ; and probably an average increase 

 of an eighth of an inch in old yews would be a nearer 

 approximation to the truth. On this latter com- 

 putation, the Gresford Yew would be about 900 

 years old, which is far more probable than its " sup- 

 , posed " planting in a.d. 426, founded on no reliable 

 record. It is stated of the yew-trees now existing 

 near the ruins of Fountains Abbey, Yorkshire, that 

 the Cistercian monks, who came there in a.d. 1132, 

 sheltered under these trees, which is 742 years ago ; 

 so that, as these yews must have been of consider- 

 able size for the monks to have found shelter under 

 them, on the lowest computation, allowing the 

 trees to have been only of the growth of 250 years 

 in 1132, they would now be without any doubt 

 nearly 1,000 years old. 



But there are many instances in which scarcely 



