32 POLYGAMIA. 



tinue falling for some time. When the air of the 

 stove in which these plants stand, is in a proper tem- 

 perature and warmth, the plants will recover them- 

 selves, and their leaves will fully expand in about 

 eight or ten minutes. I have frequently watched 

 them as they have been recovering, and have always 

 found it has been by a vibratory motion, like the in- 

 dex of a clock. 



" Some of the sorts are so susceptible of the touch 

 that the smallest drop of water falling on their leaves 

 will cause them to contract, but others do not move 

 without a much greater pressure. 



" The roots of all the sorts have a very strong and 

 disagreeable odour." 



Gum-arabic is produced from one species of this 

 genus, Mimosa nilotica, and the Gum-senegal from 

 Mimosa Senegal. 



ORDER 2. 



moECiA. SEA BUCK-THORN. Of this shrub there are 



— ~~ two species : this is found in various parts of England 



l he different * • i 



flowers on on the sandy sea coast, chiefly upon cliffs or banks 



two different ' , . 



plants. above the level of the ocean. It rises with shrubby 



stalks eight or ten feet high, flowering about the mid- 

 dle of May, and ripens its berries in the autumn, 

 which are yellow or red in different situations. 



Though the plant is often preserved in shrubberies, 

 it has never been observed to bear fruit but in a wild 



