30 P0LYGAM1A. 



dens. The annexed figure is a representation of a 

 branch of the shrub to shew the form and arrange- 

 ment of the leaves, which have so remarkable a cha- 

 racter as to contract upon the slightest external 

 stimulus. 



It appears from the works of Theophrastus, that 

 the Sensitive-plant was not unknown to the ancients : 

 he speaks of it as growing about Memphis in Egypt; 

 and Pliny also speaks of it as a plant named from con- 

 tracting its leaves at the approach of the hand. The 

 interesting phenomena connected with its irritability, 

 have been alike the subject of curiosity and scientific 

 investigation; and Professoi Martyn's observations, 

 for more than forty years, during which time he culti- 

 vated these plants, will serve to illustrate their general 

 habit and character. 



« They are more or less susceptiUe of the touch 

 or pressure, according to the warmth of the air in 

 which they grow, for those plants which are kept in 

 a warm stove contract their leaves immediately on be- 

 ing touched, either with a hand, a stick, or any other 

 thing, or by the wind blowing upon them : some of 

 the sorts only contract their small leaves, which are 

 placed along the midrib; others not only contract 

 their small leaves, but the footstalk also declines 

 downward on being touched; the first are called Sen- 

 sitive, and the second Humble Plants ; but when 

 these plants are placed in a cooler situation they do 

 not move so soon, nor contract so closely, as those 

 which axe in a greater warmth ; and those that are en- 



