368 Frevch National Instltule. 



number of genera from 7 1 to 60, which he distributes in six 

 orders. 



In a more recent memoir he asserts that he saw vipon 

 some yoLuig plants grains which appeared to him to be, si- 

 milar to the seeds of the parasite mushrooms, which are ac- 

 customed to develop themselves in the substance of these 

 plants and under their epidermis : from this he draws a con- 

 clusion contrary to a memoir of M. de CandoUe, of which 

 we shall speak shortly, that these grains traverse the epi- 

 dermis in order to lodge themselves below it. Ha further 

 dwells on certain living mushrooms, which grow by layers 

 from top to boUom, contrary to other vegetables : this ob- 

 servation was made long ago by Marsili and Bulliard ; but 

 M. dc Beauvois adds to it the idea that each layer may be 

 considered as a particular individual, or as a new mushroom 

 proceeding from the grains of the anterior layer. 



Lastly, M. de Beauvois has shown that there are consi- 

 derable differeaccs between the flowers of the raplda of 

 Oware, and those of the sagoutier of the Moluccas, so that 

 we should no longer leave them in the genus of palm-trees, 

 as hitherto done; and he has communicated the description 

 of two loldia:. 



Among the less fortunate candidates, only two of them, 

 Messrs. de Candollc and Du Petit-Thouars, have presented 

 new memoirs on this occasion. 



M. de Caiidolle, although still very young, has enriched 

 with discoveries as numerous as thev were interestins:, vege- 

 table physics, botany properly so called, and the materiij. 

 meuica. 



To the ilrst of these fcciences belong the observations he 

 made upon the iiction of artificial light, which acting at first 

 but insensibly, proceeds at last to change completely the 

 habits of vegetables : his observations upon the cortical 

 pores*; upon the production of oxygen gas by the green li- 

 chens, wliich had been denied, but of which he showed the 

 reality ; lastly, upon the vegetation of the misletoe, which 

 attracts very fast the sap of the apple-tree, w bile it cannot 

 »uck up water into which it is suddenly plunged; a fact 



which 



