408 



MONTHLY JOURNAL OF AGRICULTURE. 



gular circumstance that was brought lo light 

 during the process of converting, that is, of 

 reducing it to the form required for the pur- 

 pose to which it was destined to be applied. 

 When the main trunk was sawn through, a 

 stone of six inches in diameter was Ibnnd in- 

 closed in its substance, thi'ee feet deep*in the 

 body of the tree, and about six feet from the 

 ground when it was standing. Such or simi- 

 lar phenomena arc not of unfrequent occur- 

 rence: wo have often heard, not only of 

 stones and other inorganic bodies, but of toads 

 and serpents thus enveloped in logs or mass- 

 es of wood ; and although the alleged vital- 

 ity of the latter on exposure to the light and 

 air may be reasonably questioned , their lodg- 

 ment is far from being miraculous. There 

 are perhaps few gi'owing trees that have not 

 suffered dismemberment of a branch, or by 

 some other accident had a temporai-y hollow 

 or wound inflicted on their trunk, in which 

 a stone might be lodged by some dexterous 

 youth, or a reptile might hide itself to doze 

 out the approaching winter. The gi'owth of 

 the wood of a luxuriant tree in the spring is 

 much more rapid than might generally be 

 imagined — indeed, I may state from my own 

 observation, in some species almost astonish- 

 ing ; and the wound would be more (juickly 

 healed or closed in when thus partially filled 

 by an extraneous body, and the stone imbed- 

 ded, or the waking reptile prevented from 

 escaping by the contraction of the aperture, 

 and, after a lapse of many years, be found 

 occupying a 2>lace in the solid timber of the 

 tree, without any visible trace of the passage 

 by which it had entered or been introduced, 

 because the succeeding layers of wood, meet- 

 ing with no intenuplion in their descent, 

 would be entire. 



There is another circumstance here wor- 

 thy of notice respecting the production of the 

 wood ; it is the difference observable in 

 the thickness of the layers proportionally 

 with each other, and likewise of the same 

 layer in different parts of its circumference ; 

 the foi-mer difference depends upon the na- 

 ture of the season in which each individual 

 layer is formed, the latter uj^ou the situation 

 of the tree. You can scarcely examine a 

 horizontal or cross section of the trunk of a 

 tree, in which there is not a very manifest 

 inequality in the diameter of the different an- 

 nual deposits of its wood. Now, as I have 

 shown you that the wood is formed by the 

 descending fibres or roots of the buds, the 

 quantity produced during each season of 

 growth must depend upon the number of 

 buds developed, and the vigor with which 

 they are extended into branches ; each leaf 

 contributing, as it unfolds, its quota of woody 

 substance to the general mass. Both of these 

 will vary from a variety of circumstances, 

 more especially from the temperature and 

 vicissitudes of the season that brings them 

 forth. When the spring is cold, and sharper 

 winds prevail than ordinai-y ; when severe 

 frosty nights or mornings succeed hot days ; 



(768) 



or when a few weeks of sultry weather are 

 succeeded by a dull, ungenial atmosphere 

 and chilling rains, many of the buds, wakened 

 into action by the warmth of the sun, are cut 

 oft' by the frost and other changes of the 

 weather, and, of necessity, a less luxuriant 

 vegetation is the consequence ; the layer of 

 wood formed during that summer will be 

 thinner than that produced under circum- 

 stances more congenial. In an oak-tree that 

 Linnajus examined in the island of Eland, in 

 the Baltic Sea, he discovered, and has re- 

 corded a veiy remaikable proof of this fact, 

 in the comparative thinness of the woody lay- 

 ers, which from their situation, counting in- 

 ward or fi'om the circumference to the center, 

 he ascertained to have been produced during 

 the years 1709, 1087 and 1.578, these three 

 years being memorable in the North of Eu- 

 rope for the shortness and low temperature 

 of their summers and the severity of their 

 winters. 



In regard to the difference resulting occa- 

 sionally between opposite jiarts of the same 

 layer, it arises from similar ultimate causes ; 

 but these depend upon the situation of the 

 ti'ee. You will perhaps rarely meet with a 

 section of a trunk in which the pith, or rather 

 the place it originally occupied, which is the 

 center around which the various layers are 

 deposited, is in the exact center of the mass, 

 and frequently it is widely apart from that 

 point. When a tree grows in the heart of a 

 forest, or of a plantation, or in any equally 

 sheltered spot, the disposition of the layers 

 will be most regidar ; but when it stands in 

 an open situation, the layers of wood are 

 unifonnly found to be thicker upon the south 

 than on the north side of the trunk ; a difi'er- 

 ence probably occasioned by the sap flowing 

 with greater celerity, and the secretions be- 

 ing more abundant, on the side most exposed 

 to the influence of the sim's rays, that, while 

 they contribute to the relaxation of the ves- 

 sels, and render by their warmth the sap 

 more fluid, probably favor a more copious 

 precipitation of the carbon and other princi- 

 ples that enter into the fonnation of the 

 woody fibre. Added to this, there is gener- 

 ally a more exuberant gi-ovvth, or rather de- 

 velopment of buds upon the south side of a 

 tree that grows equally exposed ; and though 

 their fibres may not always descend perpen- 

 dicularly, it may readily be conceived that 

 they would tend toward that side of the trunk 

 where the tissue was the most yielding and 

 the secretion of the cambium most abundant. 



The mode of gi-owth we have here detailed 

 as that characterizing an exogenous or out- 

 ward glowing plant can only be understood 

 by constant reference to the compound nature 

 of those bodies which in common estimation 

 we regard as possessing an individual exist, 

 ence. Every plant, after its first develop- 

 ment from seed, becomes really an increasing 

 combination of many ; every leaf is an indi- 

 vidual, every bud multiplies and becomes a 

 family ; and these families ai-e successively 



