216 



A DISCOURSE 



OOK III. larger, it manifestly shews itself also to consist of several integuments, 

 ^^"^^^ by the circles appearing in it, as in the body ; more hard, probably, be- 

 cause straitened in room for growth ; as appears by its distending and 

 buckling, as it were, the integuments of the wood about it, so implica- 

 ting them the more ; whence a knotty piece of wood is so much harder 

 to cleave. 



It is probable that a cion or bud, upon graffing or inoculating, doth, 

 as it were, root itself into the stock in the same manner as the branches, 

 producing a kind of knot. — Thus far the accurate doctor. 



To which permit me to add only (in reference to the circles we have 

 been speaking of) what another curious inquirer suggests to us ; namely, 

 that they are caused by the pores of the wood, through which the sap 

 ascends in the same manner as between the wood and the bark ; and 

 that in some trees the bark adheres to the wood, as the integuments of 

 wood cleave to one another, and may be separated from each other as 

 the bark from the outwardmost ; and being thus parted, will be found 

 on their outsides to represent the colour of the outermost, contiguous to 

 the bark ; and on the inner sides, to hold the colour of the inner side of 

 the bark, and all to have a deeper or lighter hue on their inner side, as 

 the bark is on that part more or less tinged ; which tincture is supposed 

 to proceed from the ascendant sap. Moreover, by cutting the branch, 

 the ascending sap may be examined as well as the circles. It is pro- 

 bable, the more frequent the circles, the larger and more copiously the 

 liquor will ascend into it ; the fewer, the sooner descend from it. That 

 a branch of three circles, cut off at spring, the sap ascending, will be 

 found at Michaelmas ensuing, when cut again in the same branch, or 

 another of equal bigness, to have one more than it had at spring ; and 

 either at spring or fall to carry a circle of pricks next the bark ; at other 

 seasons a circle of wood only next it. But here the comparison must be 

 made with distinction ; for some trees do probably shoot new tops yearly 

 till a certain period, and not after ; and some have perhaps their circles 

 in their branches decreased from their bodies to the extremity of the 

 branch, in such economy and order, that, for instance, an Apple-tree 

 shoot of this year has one circle of pricks or wood less than the graft of ' 

 two years' growth ; and that of two years' growth may, the next year, 

 have one circle more than it had the last year ; but this only till that 

 branch shoot no more grafts, and then it is doubtful whether the outmost 



