©6 Ohfewalhns on the Ipomaa Hifpida. 



haufting; the patience, the fagacity, and the talents of the 

 tnoft indefatigable philofophic obferver. 



XIV. But if the vital movements are obfcure in a vcrv 

 ^reat number of animals, they become alinolt imperceptible 

 m plants. I do not here fpcak of thofe movements, fo well 

 known, of the fenfitivc plant, the hcihfarum gyrans, and the 

 Itamina of feveral others, which, as foon as touched, move 

 ■and contradl thcmfelves. It would be difficult to prove that 

 thefe movements are really vitalj and that they arife froni 

 fenfation : they-appear to me to be purely mechanical, thougVi 

 we may be ignorant of the real mcchanifm which produces 

 them ', and they have a great analogy to thofe which depend 

 on the elailicity or fpring of certain machines which, when 

 once \vound up, unbend ihemfclvcs, and continue to move 

 as long as the force and principle by which they were put irr 

 'UiStion cxifts.' 



■ XV. The indefatigable hotanift Dillon ftudied with great care 

 "the fmall trcmella^ hut he did not difcover thofe movements 

 which it conflantly nianifefts to the eve of an attentive philo- 

 fophic obferver. Adanfon went (till further, but without ob- 

 fcrving in it any thing that depends on a real principle of life 

 and fcfifation. Having become the objeft of my refearchcs, it 

 •exhibited to me a great number of movements ftill unknown, 

 and of the greateft importance. After having carefully exa- 

 mined, and, as I may fav, analvfed them, it appeared to me, 

 'as mav be feen in my works, that thev might conduft to a 

 real principle of life altogether difterent from mere mecha- 

 Tiifm. But 1 muft confels there are only two plants the life 

 and fenfation of which I was able to demonftrate in an evi- 

 dent manner, and fo as to leave no doubt; and ihefe two 

 ]>!ants are very fmali, and even microfcopic. They have 

 little' if any analogy with other plants ; and though thev ex- 

 'hibit all the properties bv which vegetables are chara6terized, 

 •Ibme even may clafs them in the animal kingdom. But 

 'whatever may be the cafe, and however important the quef- 

 •tion may appear, it cannot deftroy truths founded on fafts 

 '■and obfervations. It is much to be wifhed, for the progrefs 

 "of fcience, that the lift and fenfation of common plants could 

 be proved,' and that it were poflibic to (liow that thefe quali- 

 'ties, fo wonderful, and at the fame time fo obfcure, do not 

 ■exclufiveH' belong to animak, but that they are extended to 

 sill organized bciiKTs. 



XVF. I opened the entrance into tlii-s laborious and diffi- 

 cult path by fome obfervations, which were indeed very im- 

 pcrfcil, on the convolvuli; z. kind of ^plants which are very 

 large, and well known to every body. Animated folely by 



a defirft 



