ON THE ROOTS OF TREI 



2S5 



may not be proved to be just and true, by those who will take 

 the trouble of seeking, both in dissection and practical garden- 

 ing, that knowledge, which constant labour and watching has 

 procured me. 



The first thing that strikes the mind with astonishment in Explanation 

 the dissection of roots, is that excessive motion to which they ° ^^^^ 

 are subject ; each fibre, and each sap-vessel must be capable 

 of changing its place, and of creeping individually into ano- 

 ther situation ; and yet so admirably is the tout ensemble con- 

 trived to make but one whole, that it rarely differs from that 

 Jbrm and fold, which is allotted to that species of tree. The 

 root of a tree is that part which is the foundation of the 

 sap-vessels, I have said, that each sap-vessel of the stem is 

 joined about two inches above the earth, to two sap-vessels of 

 the root ; and so wholly and individually do they belong to 

 each other, that they ci'.nnot be divided, without causing the 

 destruction of both ; the root may, indeed, sometimes shoot 

 out another sap-vessel, I believe ; but the stem-vessel cannot 

 shoot (in this situation, and thus aggregated) another root. 

 This vessel has its little branch, flower, and fruit proportioned 

 to its size; it is impossible to know what each stem cylinder, 

 with its accompanying root, will produce, because it cannot be 

 traced higher in the tree than the trunk ; but from the root 

 to that part I have often followed it in one lengthening string. 

 Monsieur de St, Aubert, (who is pursuing the same course of 

 study as myself,) confirms what I have now written, by dissec- 

 tions published just after my opinions, in this respect, appeared 

 in your Journal ; and any one that studies from dissections, 

 must, I trust, be of the same manner of thinking, the truth so 

 plainly appears in them. To the root is added many radicles Radicles, yifk 

 with all the mechanism necessary to collect and throw up the ^l^^" i^ech;*- 

 nourishment procured from the earth around. That every 

 plant has the power, from all the variety of soils and decom- 

 posed matter, to select that which best suits its nature, and 

 convey it to the bottom of the root, where all the juices meet, 

 and are properly compounded and assimilated to the nature of 

 the plant, is a certain truth : this general reservoir is found 

 at the part where the root begins to contract, to form the sap- 

 Toot. It is known by the quantity of alburnum laid up there. 

 I have long been convinced, that alburnum, is the congealed 



juic© 



