Imperial Institute of Prance. 463 



Vegetalle and Botanical Physiology. 



M. Palisot de Beauvois has communicated to the Class 

 the result of an experiment, calculated to enlarge our know- 

 ledge upon the subject of the sap of vegetables. 



Instead of simply removing a strip of bark from around 

 2 branch, as is generally done, he entirely isolated a square 

 piece, making a cut all around, and in such a way that its 

 fibres had no longer any communication with the rest of 

 the bark, above, below, or laterally. He also removed 

 the liber and cleansed the cambium thoroughly, leaving the 

 wood only untouched at the bottom of the cut. The edges 

 of this piece of bark, thus isolated, did not cease to cxhibic 

 , vegetation, as well as the bark of the external edge of the 

 cut ; in some trees it even gave out a well -organized bud. 

 Nothing can prove more strongly the general communica- 

 tion of all the parts of a vegetable, and the manner in which 

 they mutually supply each other in their functions ; for this 

 piece of bark could only draw its sap from the wood con- 

 cealed under it. 



In our Report for 1806, we have detailed the peculiar 

 opinion of M. de Beauvois on the fecundation of the mosses, 

 and we cited at the same time the objections which still 

 prevent several botanists from adopting this opinion, which 

 consists in regarding as the pollen or fecundating powder 

 the green dust which fills the urn of the mosses ; and as the 

 seed, another dust which M. de Beauvois places in a 

 capsule situated in the axis of this very urn ; whereas 

 Hedwig takes the green dust for the seed, and looks for the 

 pollen in other organs ; and some more modern botanists 

 will not even admit of distinct sexes in these plants, regard- 

 ing this dust as heaps of small bulbs, or buds. 



M. de Beauvois has this year made a discovery which 

 confirms him in his opinion. Having carefully examined 

 the urn of the mnium capillare, he found, 1 st, That the 

 green dust of the urn did not adhere to the central capsule, 

 as it would have done if it had been the seed, and if this 

 capsule was a columella, as the followers of Hedwig assert. 

 2. That there were in the capsule transparent grains, larger 

 than those of the green dust. — 3. That in the green dust 

 itself there were grains of two kinds, some green, opaque 

 and angular, united by threads ; others transparent and 

 spherical. 



M. de Beauvois, on afterwards examining the dust of the 

 lycopodii, also found two kinds of grains in then) j some 

 were opaque and yellow, and others round and transparent, 



Yikt 



