Ohfervations on the Ipoviaa Hifplda, I7 



ft manner that one is fometimes tempted to believe that they 

 are in contaft. I have pvefented to thele plants metals, Itones, 

 and the branches of trees, iometitnes green and fomelimes 

 dry, the figures of vvliich were infinitely varied, and always 

 obferved that the fpirals they form adhere, by immediate 

 contad, to the whole length of thefe bodies, I tried to 

 change the dtre<ftion of thefe fpirals, to make them afcend 

 or defcend from left to right, if they inclined before from 

 right to left J and they always yielded to thefe changed wit!) 

 facility in a very little time. 



III. When they are r.bandoned to themfclves, and find no 

 bodies near them to which they can attach themfclves fo 

 as to climb around them, they creep along the ground, fall 

 back on themfclves, become interwoven in a thoufand dif- 

 ferent ways, and force themfclves into the ground : they ex- 

 tend to a great diftanee on every fide, and form a net of 

 fpirals clofelv united. 



IV. After haviuff long ftudied the character of thefe 

 plants, I muft confefs that I am acquainted with no mecha- 

 iiical principle by which the movements and fingular pro- 

 perties which thev exhibit can be exi)iaincd. This kind of 

 inftinft, which makes them fearch for neighbouring bodies 

 to aflift them to rife ; thofe fpirals, which they confianlly form 

 as thev grow up; thofe angles and thofe folds, which are 

 found always proportioned to the figure of the bodies they 

 meet with ; the facilitv with which their ftems, even when 

 fcxcecdingly hard and robuli, can fall back upon themfclves, 

 and form angles fo much the fmalier as the bodies to which 

 they attach tliemfelves are (lenderer: all thefe phajnomena, 

 abfolutely contrary to the reolilineal progrefs affedcd by the 

 fibres of plants, as well as by their vefiels and the liquors 

 they contain, make me fufpe6l,'in thofe which we examine, 

 a new principle of fenfation and life. 



V. It muft not be believed that the jpo?7ura hifpida thus 

 twifts round upon itfelf merely becaufe it is formed of fpiral 

 fibres, and that all its movements are only a neceflary effe-iSt 

 of its interior organizaiiun. Such an opinion is entirely void 

 of foundation. It would indeed be fruitlefs labour to fearch 

 for thefe pretended fpiral fibres by the help of the microfcope, 

 for that inltrument exhibits only rectilineal fibres and canals. 

 Befides, I have alwavs found by experience that the direction 

 of thefe plants may bd changed at plcafure ; that, if the Ipirals 

 they delcribe around anv body are formed on the right, ihcy 

 may be inuncdiately turnetl to the left, and v'tccverfa. Their 

 movements, therefore, can be al'cribed neither to any peculiar 



Vol. XII. fi mecijanifm^ 



