3 ©6 Curfory View of 



plants, and in certain parts of them, particular rcficle3 

 which, efpecially in warm weather, become filled with 

 elaftic and very fubtle excretory vapours. Thefe vapours, 

 which are accumulated and retained to a certain degree in 

 the veficles, fwell them out, and make them produce an ex- 

 tenfion in all the moveable parts where they are fituated ; 

 but on the lead fliock or agitation the elaftic and fubtle va- 

 pours which fill thefe veficles efcape, and are exhaled into 

 the atmofphere. The veficles being then emptied fhrinkv 

 and the vegetable part, which is not preferved in its ex^ 

 tended ftate, (brinks alfo, and falls back into the articulation 

 where the veficle was placed. Soon after the veficle be- 

 comes filled again, though in an infenfible manner, and ftill 

 produces an extenfion of the leaf-ftalk or petiole, which a 

 caufe like the former may deftroy. 



*' In the hedyfarum gyrans, the veficles of the bottom of 

 the fmall leaves being filled to a certain degree, then empty 

 themfelves infenfibly, become filled again as before, and re- 

 empty themfelves in the like manner, without any other de- 

 termining caufe than the effetl: of their plenitude." But this 

 continued alternation of repletion and evacuation keeps in 

 conftant movement the fmall leaves of the plant, which, when 

 the weather is warm, rife and fall alternately, but in a flow 

 manner." 



Shade, or the abfence of light, by the coolnefs refulting 

 from it, caufes that evacuation or fhrinking of the veficles 

 juft mentioned. Hence the clofing up in the evening of 

 certain parts of plants, efpecially of the leguminous families, 

 to which botanifts have given the name of their Jleep. 



It is by thefe caufes, or others analogous, that all the move- 

 ments of thefe plants ought to be explained. A great num- 

 ber of ptants experience particular movements in the fexual 

 parts at tjie time of their fecundation. Thefe movements 

 mull be produced by the aura feminalis *. 



IRRITA- 



* It may not, perhaps, be improper to take notice here of the following 

 furious circumftance refpecting a cQnferva never before found in France, 



aad 



