174 



FARMERS' REGISTER 



[No. S 



consequence, stems of this character are general- 

 ly slender. Tlie continual disposiiion ofnew bun- 

 dles of woody matter, within the unyiel(iin<: rind, 

 finally produces a tola! eolitlification of the stem, 

 and death fbliovvs as a necessary consequence. 

 Thus the lile of an endogenous stem is Hunted ; 

 ibr, unless destroyed by some external agency, it 

 must die of old age. The individual, however, is 

 eeldom destroyed; for whilst thetrunli is thus slow- 

 ly perishing, the great accumulaiion of sap in the 

 roots, causes the developemcnt ofnew shoois li-om 

 the base ol the stem, and these contiime tiie lilii 

 of the individual when the original trunk dies 

 down to the ground. In this view, the lifii of en- 

 dogenous trees is unlimited. 



In the structure ol exogenous stems, on the 

 other hand, there is nothing to limit either their 

 increase or duration ; they never die purely of old 

 age, but when destroyed, are destroyed by some 

 external agency. The central wocd" of exogens 

 it is irue, dies in the course of time, but the death 

 of the stem does not lullow as a consequence of 

 this ; for nothing is more common than to see a 

 tree hollow, destroyed at its centre, whilst it, is 

 growing vigorously at its circumli?rence. The 

 sycamore ( planianus occidentalis ) furnishes a 

 remarkable and well known illustration of this. 

 The oldest truid<s are generally all destroyed, ex- 

 cepting a lew of the outer and recently Ibrmed 

 layers, which prolong the existence ol' the mdi- 

 vidual. 



Some instances of grea size, and extreme lon- 

 gevity in exogenous trees, where the statement 

 can be relied upon, may not be uninterestinir. 

 The pinus lambartiana, a species of pine indi- 

 genous to northern Calilbrnia, probably attains a 

 greater size than any other known tree. One 

 specimen, measured by Mr. Douglas, an English 

 iboianisi, 'nvas '215 leet in height, 57 feet 9 inches 

 in circumlerence, at a distance of three leet from 

 the ground, and 17 Itjet 5 inches, at 134 feet ; thus 

 giving as the solid contents of the trunk alone 

 about 1200 cubic lijet. This was probably, the 

 largest single mass of timber ever measured by 

 man." — "A sycamore growing near JV'larieila, 

 Ohio, measures 15.^ leet in diameter;"' or suppo- 

 sing It cylyndrical, more than 45 leet in circum- 

 lerence. There is said to be "an oriental syca- 

 more, growing near Constantinople, 150 leet in 

 .drcumlerence, with an internal cavity of SO leet." 

 "The largest oak known in England, was called 

 Damony's oak, in Dorsetshire, and was 68 Itiet in 

 circumlerence. With respect to ihe age of trees, 

 it may be remarked, that an elm has been to reach 

 the age of 335 years, an ivy 450, ;.n orange 630, 

 an ohve about 700, a cedar of Lebanon "800, a 

 vvhiie-oak 1080, and a yew between 13 and 1400. 

 De Candolle estimates the age of a Mexican cy- 

 press at 6000 years ; but then his estimate was 

 formed by dividing the semi-diameter of the trunk, 

 by the average thickness of the layers of that 

 species of tree, and Ibr reasons before mentioned 

 cannot be relied upon. If it were indeed so old, 

 its young shoot, must have been watered by the 

 waves of the deluge. The most aged, as well as 

 the largest trees, in the northern pa^ts of the Uni- 

 ted Slates, belong to the species plantanus occi- 

 dentalis American plane-tree, as it is called in 

 Europe, or butter-ball, as it is called in New Eng- 

 land, or sycamore as it is more commonlv called 

 in the western and Boulhern states. The largest 



and most aged trees, indigenous to the southern 

 states, belong to the species cupressus Ihyoides, 

 white cedar as it called in New England, or cy- 

 press as it is more commonly called at the south. 



If we compare an exogenous with an endoge- 

 nous stem, we are, at first sight, unable to discover 

 any analogy between them ; but on a mure care- 

 ful inspection, we will find that llie principal dif- 

 ference in the arrangement of their materials con- 

 sist in this : that in the Ibrmer, the woody fibres 

 and vessels, are disposed throughout the cellular 

 portion of the stem, in the form of concentric 

 zones, irregularly intersected by the medullary 

 rays; whilst in "the latter, they are arranged aa 

 bundles, irregularly [)laced throughout the stem. 

 If we examine a transverse section of one of the 

 bundles, with a good microscope, we will find ii 

 to be concavo-convex, with its convexity turned 

 towards the outside of the stem. The convex or 

 outer side, will be found unilbrndy more solid than 

 the concave or inner side. Now if we suppose 

 the medullary rays lo be continuous throughout 

 the length of the stem, they must cut the zones of 

 an exogen up into bundles, very similar to ihose 

 of an endogen. The meuullary rays in an exo- 

 gen, are but parts of the pith, consisting like that 

 of cellular tissue only, and owing their peculiar 

 flattened appearance to the extreme pressure to 

 which they are subjected by the growing wood. 

 If in consequence of the wood's being more loose- 

 ly arranged, this pressure was removed ; their 

 cellules would have the same form as those of the 

 pith; indeed, the two would be undistingnishably 

 blended together; and thus an exogen would as- 

 sume very nearly the appearance of an endogen. 

 We do not mean to make the impression, that 

 these changes ever do take place ; hut only by 

 supposing them, to point out more distinctly the 

 resemblance which these two kinds of stems have 

 to each other. 



JBesides these two kinds of stems, which are by 

 far the most common, there is a third kind, met 

 with only in lerns, and a lew other closely allied 

 genera of plants. In its general arrangement it 

 resembles the endogenous method, but differs 

 from it in this, that the woody bundles instead 

 of presenting, on a transverse section, a cir- 

 cular or crescent shaped figure, appear "like a 

 number of sinuous lines, doubling about among 

 spongy matter." These bundles never increase 

 in thickness, number or quanlity, after being once 

 Ibrmed, and of course this class of stems do not 

 increase in diameter at all, but are able to length- 

 en only by the addition of new matter to their ex- 

 tremities. Hence, they have been termed acro- 

 gens. As this structure is very uncommon, and 

 but little understood, in such an essaj' as the pre- 

 sent it cannot claim more than this passing notice. 

 (Tb be continued.) 



GREAT DROPS OF WHEAT IN NEAV HAMPSHIRK. 



Josiah Stevens, Esq., of New Hampshire, Secre- 

 tary of State, raised last season on one acre of light 

 soil upon his farm in Newport, very near thirty 

 bushels of the common bearded wheat. He sowed 

 upon this acre fbur bushels of dry slacked lime 

 made at Welhersfield, Vt. Mr. Stevens is of 

 opinion that hiserop of wheat was doubled in con- 

 sequence of the application of the lime. One 

 bushel and a half of wed was sowed. — [Mon. 11*' 



