336 ON THB ROOTS OF TREES. 



juice into which all the various nourishment o' the earth (urns.j 

 part forms into sap, part into the jelly of wood ; for he sap is 

 nothing but this juice in a dissolved state, and the woo ■ nothing 

 more than alburnum, having the wood and bastard vessels 

 lengthening by degrees, and running through it. It is im- 

 possible, that any wood ves-sels can be formed by this juice, but 

 the sap may easily be converted into that jelly-like substance, 

 which forms ihe allumum, and the rest of the process may 

 be seen to pass under your eye in the solar microscope ; that is, 

 the bastard vessels may be seen to lengthen, and the sap- vessels 

 to pierce through the softer substance, for the completion of 

 the wood. 

 First part of The root may be divided into three parts ; the first part 

 the root. shows the difference between the stem and rooi, the latter 



having double the numler of wood vessels, and no pith j for 

 No pith after after tEe first three or four years, the pith always disappears in 

 tjxi uurd year, j^g j-oot of trees, and the line of life occupies the centre in its 

 stead ; indeed, as the chief use of the pith is to moisten the 

 wood vessels, that they may bend in every direction, and thus 

 tacilitate the exit of the buds ; and as the roots of trees have 

 few buds after that time to throw from the root, the pith would 

 no longer be of use in the centre ; the bark and inner bark are 

 nearly the same as in the stem, and the row of alburnum ra- 

 ther larger— that the wood should be double in the root, to what 

 it is in the stem — and that it should increase according to the 

 increasing branch, is the most absolute proof that the sap flows 

 iu the woud, since no other part would produce nourvshmeni 

 fufiScient to support the tree. But no person who dissects 

 trees, can doubt this truth, as the immense sap-vessels, and 

 their being loaded with sap, must carry conviction to the most 

 incredulous, provided they see it properly magnified. 

 Second part of "^'^^ second part of the root is that which appears to be the 

 tLe root. reservoir. It has all the parts already mentioned, except that 



the bark is narrower, and that the part usually occupied by the 

 alburnum, has from three to five rows of that matter. Instead 

 of one 3 they are wide and juicy, and the quantity most irre- 

 gular. I have often seen them almost heaped together, forming 

 at once from five to seven rows j but 1 never saw more. 

 (See fig. 1 . PI. 8.) The alburnum is loose and thin, and far more 

 watery and unfinished in its appearance, than ia the stem, or 



first 



