VOL. VII.] PHILOSOPHICAL TRANSACTIONS. 35 



part of the spongy parenchyma, and no signs of milky juice follow, that is, no 

 breach of a vein. Again, we have stripped the plant of its skin, by pulling it 

 up by the roots, and exposing it to the wet weather, until it became flaccid as 

 a wet thong, without any injury to the veins, which yet upon incision would 

 freshly bleed. These experiments make against the general opinion of one only 

 sap loosely pervading the whole plant, like water in a sponge. And though we 

 have made these, and many other experiments, to facilitate an ocular demon- 

 stration of these veins ; yet we have not been able to effect it to our mind, and 

 subject them as nakedly to our eye as we could wish. 



In the transverse cuts of plants, we see as it were a certain order and number 

 of the bloody orifices of dissected veins. We observ^e also in a leaf, which we 

 take to be the simplest part of a plant ; 1 . That the veins, &c. keep company 

 with the ribs and nerves, as we vulgarly call them, and are distributed into all 

 the parts of the leaf, according to the subdivisions of those nervous lineaments, 

 and are disposed with them into a certain net-work. — 2. That in a transverse 

 cut of a leaf, the middle fibre or nerve, for example, seems to yield one large 

 drop of a milky juice, springing as it were from one vein; yet the microscope 

 plainly shows us, that there are many veins which contribute to the making up 

 of that drop. — 3. That if a fibre or nerve be carefully taken out of the leaf, the 

 veins will appear in it like so many small hairs or pipes, running along and 

 stripping the nerve. — 4. That those many veins are all of an equal largeness, for 

 ought we have yet discerned to the contrary. — 5. That though we seem to be 

 more certain of the ramifications of the fibres, wherein those veins are, we vet 

 are not so, that those veins do any where grow less and smaller, though pro- 

 bably it may be so, — 6. That we cannot discern any where, throughout the 

 whole plant, larger or more capacious veins, than those we see adhering to the 

 fibres of the leaves ; which do also appear from comparing the bleeding orifices 

 in a transverse cut. I have found it a difiicult and laborious task, to trace and 

 unravel them throughout the whole plant. 



- Our opinion is, that these veins do still keep company with their respective 

 fibres. And as all the fibres of the leaf are joined in the stalk of the leaf, and 

 that stalk explicated in clothing the twig or stem of the plant, so do we think 

 of the veins, their perpetual companions. — But moreover, in the roots of plants, 

 if a simple coat be separated and exposed between yoxir eye and the light, the 

 veins appear to be strangely entangled and implicated, and not in the same 

 simple order as in the leaves. — From what has been said, it may well be doubted, 

 whether there is any sinus or common trunk, into which all the veins are 

 gathered ? But rather that there are a multitude of equally large veins, each 

 existing apart by itself. We indeed have found it very difficult so to exhaust 



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