VOL. XXIV.] PHlLOSOPHrCAL TRANSACTIONS. |pj 



by its having surrounded two several divisions of the horizontal vessels. W« 

 may pretty easily conceive how one canal is produced, or issues out from an-f 

 other ; but how the said long sharp pointed particles, represented by fig. 8, Q, 

 10, 11, are produced, is, as well as a great many other phaenomena, past my 

 understanding. 



I have also examined into the nature of the bark of a thick lime tree ; the 

 rather because I know no other barks of trees whose parts are so easily separated 

 from each other, either in length or breadth; insomuch that in Muscovy they 

 make of it mats for packing, and rope-work, which is very strong, and if I am 

 rightly informed, is not easily subject to rot, though it should lie long wet. 

 This bark I also cut across, to discover the bent or run of the horizontal vessels 

 that issue out of the wood. Fig. 12 represents a small particle of the bark of a 

 lime-tree, as it was cut across; where abc show the horizontal vessels that 

 issue out of the wood, and consequently they are cut lengthwise. These vessels 

 although at their first issuing out of the wood they lie close to each other, as 

 from A to B, and from b to c ; yel they do not remain always so close ; but as 

 the tree grows thicker and larger, the horizontal vessels are more divided from 

 each other; as for instance, that which at b is but one bundle or collection 

 of vessels, with the increase of the tree divides itself into two, and the 

 separation grows larger and larger, as in bmk and bml. Now, that there 

 may remain no interstice or vacuity between the said horizontal ves^el^, 

 there are other vessels produced from those, as seen between mid, which new 

 vessels produce a matter that fills the place of mlk. These parts are roundish, 

 but so interlinked with each other, that they servp for canals. They do not 

 run through the thickness of the old bark; for in some places the bark dies 

 sooner than in others, for want of nourishment; insomuch that you may per^ 

 ceive in the bark of a lime-tree, of an ordinary thickness, three distinct crusts, 

 lying one upon another, the outermost of which being destitute of nourishment, 

 by little and little become dry and withered. Fig. 13 represents a very small 

 particle of the bark of a lime-tree ; wherein are shown partly the mouths of tha 

 canals that lie lengthwise in the bark, and are here cut across ; but chiefly to 

 give a view of the horizontal canals, as they are cut in their length, as at ns or 

 pQ ; which same horizontal vessels are represented in fig. 12, by aih, bmlg, 

 BMKF and ODE. These canals or vessels, described by ns or pa are not of a 

 continued hollowness throughout, but rather seem to consist of oval particles 

 linked to each other, 



I placed before a microscope a little bit pf a lime-tree, which vyas cut off the 

 wood lengthwise, and the horizontal vessels cut across ; to see how those hori- 

 zontal vessels or canals lie in the wood ; which vessels are also continued into 

 the bark, so far as it is alive, and serve for the feeding and increasing of it. 



