VOL. VI.] PHILOSOPHICAL TRANSACTIONS. 063 



4. The insertment and pith, proceeding also from the plume, as the same in 

 the root from the radicle ; so that, as to their substantial parts, the lobes of 

 the seed, the radicle and plume, the root and trunk, are all one. Here notice 

 is taken of the shooting of the lignous body in breadth ; wherein are observable 

 its fibres, production of rings, and especially pores ; and these of three sorts, 

 greater, lesser, and least of all ; all continuous and prolonged by the length of 

 the trunk : which he proves by an experiment made by Mr. Hook, by filling 

 up (suppose in a piece of charcoal) all the said pores with mercury, which ap- 

 pears to pass quite through them, as is visible by a good glass. The result of 

 all is, that the woody part of a vegetable is nothing else but a cluster of in- 

 numerable and extraordinary small vessels or concave fibres. He farther shows 

 the insertions of the cortical body in the trunk, and the pores of those inser- 

 tions ; in none of which pores he could observe any thing that may have the 

 true nature and use of valves ; the non-existence of which he is asserting. He 

 discourses also of the position and course of the pores : and concludes this 

 chapter by declaring, how the trunk ascends ; how its parts, in consequence of 

 that ascent, are disposed ; how that disposition is consequent to the different 

 nature and energy of the sap ; what the effects are of that difference ; which 

 way, and how the sap ascends, viz. by the joint subserviency of the lignous 

 and the cortical body in some, but in most, and principally, of the lignous 

 body and pith ; the latter being here considered as a curious iiltre of nature's 

 own contrivance : where he examines, how the pores of the pith are permeable ; 

 and renders a reason why a piece of dry elder pith, set in some tinged liquor, 

 the liquor does not then penetrate the pores, so as to ascend through the 

 body of the pith ? To this part is annexed, by way of appendix, some con- 

 siderations of the trunk-roots and claspers, and the use of both. 



After this, he proceeds to the germen, branch, and leaf, and finds in the 

 two former the same parts with those of the trunk, viz. the same skin, and the 

 same cortical and lignous bodies, as also the same insertment and pith, here- 

 into propagated, and distinctly observable in it. Further, he shows the man- 

 ner of their growth and nutrition, and how the germen is secured ; as also the 

 use of the knots. Then he lays open the parts of a leaf, and explains the po- 

 sitions of the fibres in the stalks of leaves, and the cause of their different 

 shape, and of their being fiat. Then he discourses of the folds of leaves, their 

 kinds and use, with the uses of the leaf itself. To this chapter also he makes 

 an appendix, concerning thorns, hairs and globulets, explaining both their 

 constitution and use. 



Next he gives an account of the flower, and its three general parts, the em- 

 palement, the foliation^ and the attire ; explaining the formation, nature, and 



