152 VEGETABLE OUGANOGRAPHY. 



found that if the branch sur\aved this operation and bore 

 fruit, these fruits had stones as usual. " Finally, the 

 presence of the pith in branches which are not destined 

 to bear flowers, sufficiently proves that the use of this 

 organ is not connected with the flowering. 



Borelli and Hales attribute to the pith a powerful 

 action in vegetation ; they think that this spongy sub- 

 stance, placed at the extremity of the branches, attracts 

 the moisture ; that it adheres there strongly ; that the 

 sun endeavours to separate it ; and that from this action 

 results the elongation of the fibres : this explanation is 

 so far removed from the more simple notions of phy- 

 siology, that it is needless to refute it. 



Malpighi thought that the sap ascends through the 

 wood, that it is carried into the pith through the medul- 

 lary rays, and that there it receives a peculiar elaboration. 

 Plenck, who adopts the idea of Malpighi, adds that the 

 pith is a receptacle of the nourishment which the young 

 shoot absorbs in the time of drought. These last authors 

 came very near the truth ; but they have too much 

 neglected an essential circumstance, viz., that the pith 

 has no physiological life, action, or existence, but 

 during the first period of the development of the bud ; 

 and that, when this epoch has passed, it becomes flaccid 

 and useless ; it is then a receptacle of nourishment 

 destined to support the young shoot until it has de- 

 veloped its leaves, when it can obtain it for itself. It 

 is, if I may thus venture to express myself, the Cotyle- 

 don of the bud, provided that this expression is employed 

 in connexion with the physiological use of the organ, 

 and not with its organographical function. 



Such is the manner in which, from general facts, I 

 have represented the use of the pith in the public course 

 of Vegetable Physiology which I gave in the College de 

 France in 1802. Since then I have had the satisfaction 



