88 



ON ORGANIZED BODIES, 



vegetables consists of nothing more than a mere spongy cellular substance, 

 forming, indeed, an admirable reservoir for moisture; and hence of the 

 utmost importance to young plants, which, in consequence of their want of 

 leaves and branches, whose surfaces are covered with the bibulous mouths of 

 innumerable lymphatics, would otherwise be frequently in danger of perish- 

 ing through absolute drought ; but gradually of less use as the plant advances 

 in age, and becomes possessed of these ornamental appendages ; and hence, 

 except in a few instances, annually encroached upon, and at length totally 

 obliterated by the surrounding lignum. 



All these lie in concentric circles ; and the trunk enlarges, by the formation 

 of a new liber or inner bark every year ; the whole of the liber of one year, 

 excepting indeed its outermost layer, which is transformed into cortex, 

 becoming the alburnum of the next, and the alburnum becoming the lignum. 

 Such, at least, is the common theory, and which seems to be well supported 

 by the experiments of Malpighi and Grew : but it has lately been controverted 

 by Mr. Knight, who contends, that the liber has no concern in the formation 

 of new wood, which proceeds from the alburnum alone, a new layer of albur- 

 num being formed for this purpose annually. I cannot discuss the argument 

 at present; nor is it of any great importance ; since, under either system, it 

 is obvious that a mark of any kind, which has penetrated through the outer 

 into the inner bark, must in a long process of years be comparatively trans- 

 ferred to the central parts of the trunk. On which account we often find, in 

 felling trees of great longevity, as an oak, for example, the date of very 

 remote national eras, and the initials of monarchs, who flourished in very 

 early periods of our national history, stamped in the very heart of the timber 

 on its being subdivided. 



Some of these memorials are very curious, and M. Klein, the well-known 

 Secretary of Dantzic, has given various examples in his letter to Sir Hans 

 Sloane, bart., the President of the Royal Society.* One of these consists of 

 a long series of letters discovered, in 1727, in the trunk of a full-grown 

 beech, near Dantzic, in land belonging to the family of Daniel Berckholtz. 

 The letters D. B. v/ere chiefly conspicuous in the solid wood ; the wood 

 towards the bark, and that towards the heart, that is, in each extremity^ 

 "bearing not the least trace of letters." M. Klein relates another example 

 from the Ephemerides of Natural Curiosities,! recorded by Joannes Myerus, 

 It consists of a thief hanging from a gibbet, apparently drawn by nature's 

 own pencil in the timber of a beech-tree : as also the figure of a crucified 

 man, found in a tree of the same kind ; and that of a chalice with a sword, 

 perpendicularly erect, sustaining a crown on its point ; which was preserved 

 at the Hague, and had been seen by himself. 



Such marks were formerly attributed to miraculous intervention, or regarded 

 as marvellous sports of nature : but the hints now oflfered will easily explain 

 their origin. 



Foreign substances have often been found imbedded in the same way, 

 having at one time been sunk into the inner bark, or penetrated it by a wound 

 or other excavation, and afterward covered over with new annual growths 

 of liber and alburnum. Thus Sir John Clerk gives an account of a horn of a 

 large deer which was found in the heart of an oak in WinfieldPark, Cumber- 

 land, fixed in the timber with large iron cramps, with which, of course, it 

 had been fastened on.| And we are hence able to account for the occasional 

 detection of a Capricorn beetle,^ or other insect which has been found in the 

 centre of a trunk, the animal having crept into an accidental cleft, and either 

 died there naturally, or been arrested and imprisoned by the secretion of the 

 matter of new inner bark while in the torpitude of its aurelian state. And 

 hence, indeed, the cause of the very wonderful phenomena of toads or frogs 

 oeing at times found in a like situation ; having in the same way been 

 impacted in the hole or crack into which they had crept, by the glutinous 

 fluid of the inner bark, during sickness or a protracted winter sleep. Some 



* Phil. Trans, for 1739, vol. xli. p. 231. t Ephem. Nat. Cur. decad. iii. an. v. obs. 20. 



t Pbil. Trans, for 1740, vol. xlL p. 448. $ lb. 1741, vol. xli. p. 861. 



