238 On the Buds and Ram'ificatioiis of Plants, 



is sometimes also at the base, and Very near the largest 

 herbaceous body, a similar body, which penetrates with it 

 into the same bud. All these herbaceous bodies are produced 

 each separately i/i a medullary sheath, and never in the 

 bark, the Hber, or the alburnum, nor in the annual zones 

 ot the wood. They are indeed the prolongations of the 

 bundles of tubes of the medullary sheath*. 



The herbaceous bodies of" which I here speak, in passing 

 into the wood are not always in a horizonlal direction: I 

 mean, that they do not form in all the plants which I have 

 examined a na;ht angle with the medullary sheath : in se- 

 veral trees and shrubs they leave it much lower than the 

 pface where the bud issues From the bark, as is the case 

 in the shumac, plane-tree, willows, &c. 



When the bark, with the bud, has been removed, these 

 herbaceous prolongations present themselves under different 

 forms, according to the species to which they belong, the 

 age of the branch, the place even where they are, and the 

 angle at which they have traversed the wood. This is the 

 reason why the figure of their section in the exterior zone 

 of the wood varies from the form of a line or stroke to that 

 of a point entirely rc/und ; sometimes there are several of 

 them united, so that altogether they form scarcely a single 

 line or oblong point. At the place where these herbaceous 

 bodies traverse the wood, the ligneous fibres are separated 

 from each other; and though they press them more or l(;ss, 

 they still leave them a sufficient passage. This separation 

 of the tubes and fibres of the wood is more apparent in the 

 zones near to the medullary case, than in those which are 

 more distant, and consequently nearer to the bark. 



The thickness of these bodies differs also in the different 

 Species of plants. In those the wood of which is hard and 

 compact they are smaller, and at the same timeless cylin- 

 dric than in those the wood of which is light. Those de- 

 stined to push forth buds for twigs and flowers have more 

 volume than those which produce leaf-buds. 



Thev do not always remain green ; they lose that colour 

 as they change into wood. But they are found herbaceous, 

 and filled wUli green substance, at least, until the bud has 

 expanded into a flower-bud ; and I have observed that they 

 are stil! green and herbaceous, even in the twigs and young 

 branches, if the wood of the species from which they have 

 proceeded be white and light. 



* These vessels are porous tubes, large simple tubes, trachese, and false 

 trachea. See Trai.e d'^lnal^tnie et dc Phyno'.ogie veg<ltiks, par Brisseau Miriel, 

 vol. i. p. 18G, et scq.; and ihe same in Diet, dcs Sciences NaturclUs, vol. ii. 

 p. 369. 



5 The 



