SOS SCIENTIFIC SEWS. 



duced'the number of genera of the mushrooms to sixty, 

 which he distributes, into six orders. 

 Seeds of the pa- In a subsequent essay he asserts, that he has seen on young 

 rasmc fungi plants particles appearing to him similar to the seeds of pa- 

 the epidermis rasitic funguses, that are accustomed to unfold themselves 

 of plants. j a ^g su bstance of Vac plants, underneath the epidermis : 



and hence he concludes, in opposition to Mr. Cando!Ie, that 

 these grains pass through the epidermis, to lodge themselves 

 bene.ith it. 

 Mushrooms in- He treats more largely on certain mushrooms, that grow 

 creasing by ho ^y layers from the top downwards, contrary to other vege- 

 tables. This observation is not new ; but his opinion is; 

 for he considers each layer as a new mushroom, produced 

 from the seed of the layer above it. 

 Theraphiaof He has likewise shown, that the flowers of the raphia of 

 £^ r ™ff^ cnt Owerra differ too widely from those of the sago tree of the 

 tree. Moluccas, to continue them in the same genus of palms. 



Mr. deCan- An unsuccessful competitor of Mr. de Beauvois was 



Mr. de Candollc, who, though young, has distinguished 

 himself in vegetable physics, as well as in other branches of 

 Action of artifi botany. Among his labours may be particularly noticed his 

 plants 5 > ° n observations on the action of artificial light, which, operating 

 at first imperceptibly, at length effects a total change in the 

 Production of habits of vegetables : on the cortical pores : on the produc- 

 chens" * '" t ' on °* ox '» eu S as D y green lichens, which has been denied, 

 The mistletoe but tivfe reality of which he has proved: and on the vegcta- 

 notwater! 15 ' bUttion of mistletoe, which really attracts the sap of the apple- 

 tree, but cannot draw up water, in which it is directly im- 

 mersed; a fact of importance with respect to the cause of 

 the ascent of the sap in plants. 

 Parasitic fun- Mr. Candolle presented three memoirs to the class on the 

 guses * occasion. The first was on those parasitic funguses, that 



develop themselves beneath the epidermis of plants, and 

 cause several fatal diseases, as the blight in corn. (See 

 Journ. vol. X. p. 225.) It has been supposed, that the 

 seeds of this plant were introduced through the pores of the 

 Their seeds in- epidermis : but as coloured liquids traverse these pores with 

 pl&ntsb "the difficulty, and simple application does not inoculate the 

 roots. plants with these diseases, he conceives the seeds to be in- 



troduced by the roots with the nutritions juices, and circvu 



late 



