On the Buds and Ramifications of Plants. 3L'3 



the twigs of several trees and shrubs, such as the voung 

 branches of the common willow [sdl'ix caprca), a considera~ 

 ble number of small herbaceous prolongations of the mc- 

 dullary sheath, which were as insulated and dispersed 

 throughout the ligneous body, and which had neither 

 pierced nor raised up the bark that covered thcni. They 

 appeared to me to be prolongations reserv'ed to form, in 

 case of need, leaves or branches. 



But how can we account for the origin of buds from a 

 trunk the interior part of which is rotten, and where the 

 medullary sheath rxo longer exists ? and how comes it to 

 pass that the branches of a hollow tree, or those grafted on 

 another tree, vegetate with tht greatest vigour? It appears 

 to me that the answer to this question presents no difficulty. 

 These phenomena w-ill soon be e.\plained,if vv-e shall be able 

 to prove that the prolongations of the sheath may be pre- 

 served, and livCjwifen they arc separated by art or by naiure 

 from the sheath wheiTce they have arisen. In these cases 

 the branches racist receive the, sap by other t-ubes than those 

 of the sheath. But does not the observation made by 

 Cimlomb, that in sound trees the sap ascends chieHy by 

 the tubes whicti surround the pith, oppose what I have 

 said ? I do not think it : on the contrary, I am of opinion, 

 that, if the observation of that celebrated philosopher had 

 ftill need of being corTobcjrated, it certainly would be by 

 my experiments on the prolongations of the sheath. It is 

 in these organs indeed, more than iu any other, that we 

 are to search f&r the proof tbat the sap ascends chiefly in 

 the vessels of the medullary sheath of a sound tree, because 

 when cut transversely they are always found, as Jong as they 

 are not ligneous, more or less filled with juices. But is the 

 medullary sheath the only way by which the sap proceeds 

 from the root to the extremities of the vegetable ? Has na- 

 ture confined herself within so narrow limits, or has she 

 established other canals to conduct the nourishing juices 

 from the root to all the ramifications of the plant ? The 

 existence of so many hollow trees will furnisli us with an 

 answer. In hollow trunks it is only bv the lilier, and be- 

 fore the birth of that organ by the alhiirmnn, that nature 

 makes the sap to ascend. It happens also, but more rarely, 

 that the bark is provided with small tubes which convey a 

 part of that limpid liquor. If we examine the hollow wil- 

 lows on the approach of spring, it will be observed that the 

 aliurnum is full of juice. If we cut the stems, branches, 

 and stalks of the vine, euphorbia, 8cc. we shall see the tubes 

 next the bark emit not only their o\vu juices but alio an 

 X 4 aqueous 



