SECT. XIII. 4. OF VEGETABLE ANIMATION. 109 



like the former, cannot be owing to irritation, as 

 the irritating material is withdrawn. 



The approach of the anthers in many flowers to 

 the ftigmas, and of the piftils of fome flowers to 

 the anthers, muft be afcribed to the pallion of love, 

 and hence belongs to fenfation, not to Irritation. 



III. That the vegetable world poflefies fome de- 

 gree of voluntary powers, appears from their ne- 

 ceflity to ileep, which we have (hewn in Sect. 

 XVIII. to confift in the temporary abolition of vo- 

 luntary power. This voluntary power feems to be 

 exerted in the circular movement of the tendrils 

 of vines, and other climbing vegetables ; or in the 

 efforts to turn the upper furface of their leaves, or 

 their flowers to the light. 



IV. The aflbciations of fibrous motions are ob- 

 fervable in the vegetable world, as well as in the 

 animal. The diviiions of the leaves of the fenfitive 

 plant have been accuftomed to contract at the fame 

 time from the abfence of light ; hence if by any 

 other circumflance, as a flight ftroke or injury, one 

 divifion is irritated into contraction, the neigh- 

 bouring ones contract alfo, from their motions 

 being affociated with thofe of the irritated part. 

 So the various ftamina of the clafs of fyngenefia 

 have been accuftomed to contract together in the 

 evening, and thence if you ftimulate one of them 

 with a pin, according to the experiment of M. 

 Colvolo, they all contract from their acquired af- 

 fociations. 



To evince that the collapfing of the fenfitive plant 

 is not owing to any mechanical vibrations propa- 

 gated along the whole branch, when a fingle leaf 

 is ftruck with the finger, a leaf of it was flit with 

 (harp fcifibrs, and fome feconds of time palled be- 

 fore the plant feemed fenfible of the injury ; and 

 then the whole branch collapfed as far as the prin- 



1 2 cipal 



