360 Proceedings of the + 



loped to admit of the communication between the upper and lower 

 part of the trunk being sufficiently re-established, or the develop- 

 ment is insufficient for that purpose : in the first case, the buds are 

 saved, because their roots attain the earth ; in the second, they are 

 exposed to die of inanition, and the tree will perish with them, as 

 they have no root. This hypothesis of La Hire excited so little at- 

 tention, that when the same thing was asserted nearly a century 

 afterwards by Du Petit Thouars, every one (including probably that 

 learned naturalist himself) believed it an entirely new theory. For 

 twenty-five years Du Petit Thouars defended it with a perseverance 

 worthy of a better cause, but he gained no proselytes, as the experi- 

 ments made by Duhamel and others demonstrated the fallacy of his 

 reasoning ; but a new supporter of it having come forward in the 

 person of M. Poiteau, the committee nominated by the Academy 

 have made the following fresh experiments : If a large ring of bark 

 be taken from the trunk of a sycamore maple, and replaced by a 

 similar ring from the bark of a red maple entirely devoid of buds, 

 the latter will graft itself as a cutting or graft would do, and below 

 it a bed of red maple wood will speedily be developed. The grain 

 of the wood will leave no doubt as to its nature. This ligneous 

 production cannot be derived from the buds of the red maple, 

 because the ring of bark was devoid of any ; nor can it result from 

 those of the sycamore, because they could only produce sycamore 

 wood. It must, therefore, owe its origin to some other cause than 

 the lengthening of the roots of the buds : and even if the bed of 

 wood formed in the trunk of the sycamore below the ring of red 

 maple bark were to be sycamore, and not red maple wood, still, as 

 this bed of wood would be separated from the corresponding bed in 

 the upper part of the trunk by the whole width of the ring of red 

 maple bark, it is impossible to imagine that it could spring from the 

 buds of the sycamore. Again, if a large ring of bark be taken from 

 the trunk of a vigorous elm, or one of many other dicotyledonous 

 trees, without being replaced by any thing, new beds of wood will be 

 formed in the lower as well as in the upper part of the trunk, while 

 no ligneous production will appear on the ring of wood left exposed 

 by the removal of the bark; the formation, therefore, of the buds on 

 the lower part of the trunk cannot be attributed to the development 

 of the supposed roots of the buds, as they could not descend from 

 the top of the tree to the earth through the exposed ring of wood 

 without being perceived. The present memoir contains no new 

 facts, but merely gives the theory the powerful support of M. Poi- 

 teau's opinion ; the reporters, therefore, conclude, that, as the theory 

 of La Hire is in direct contradiction to facts, the Academy cannot 

 bestow its approbation on the memoir of M. Poiteau. 



Generation of Plants. At the same meeting, Messrs. Sylvestre, 

 Mirbel and Cassini presented the following report on a memoir by 

 M. Giroux de Busaringues, entitled * Sur la Generation des Plantes et 



