274 0/ the Pith of Trees* 
compofed of a great number of other lignous fibres, with 
which alfo the parenchymous are intermixt. 
Fig. 516. exhibits a parcel of the fame vefiels in the 
wood of fir, greatly magnified ; and at a, is feen the fame 
piece of its natural fize. 
Fig. 517. AB fhews a lymphaeduft, and fig. 518. C, 
reprefents a ladliferous vefiel, both of which are fur- 
rounded with parenchymous bladders, and are greatly 
magnified. 
Fig. 519. reprefents part of the ftalk of fumach, fome- 
what larger (and more magnified) than that of fig. 494* 
with feveral breaks in it, to fhew the contexture both 
of the perpendicular and horizontal fibres ; in which, as 
before, AB a a fhews the hairy Ikin : ABCD the bark 
in which the fibres b b, c c, and d d, that hang down 
therefrom, are lymphsedudts, one of which d d d, is com¬ 
pofed of a great many other fmaller fibres : HWI the 
parenchyma: D M C the common lymphaedudls: KML 
the milk veffels compofed of bladders : H I another fort 
of lymphaeducts arched over the milk vefiels : DCEF 
the wood, from which the fibres e f, that hang down* 
are fome of them the old lymphsedudls turned into wood;, 
g h g h are two air vefiels in which the wreathing thereof 
is plainly feen, and from h to i is alfo feen part of the. 
fame vefiels unwreathed : O P is part of one of the infer- 
tions compofed of bladders, and thofe bladders of threads r 
E F G are parts of the pith compofed of thready os 
fibrous bladders» 
Of 
