144 PHYSIOGNOMY OF PLANTS. 



east side of the Alleghany mountains, as far north as the 

 38th parallel, and on the west side even as far as the 41st 

 parallel. Gleditschia monosperma ceases two degrees farther 

 to the south. These, are the limits of the Mimosa form in 

 the northern hemisphere. In the southern hemisphere we 

 find beyond the tropic of Capricorn simple leaved Acacias as 

 far as Yan Diemen Island ; and even the Acacia cavenia, 

 described by Claude Gay, grows in Chili between the 30th 

 and 37th degrees of south latitude. (Molina, Storia Natu- 

 rale del Chili, 1782. p. 174.) Chili has no true Mimosa, 

 but it has three species of Acacia. Even in the north part 

 of Chili the Acacia cavenia only grows to a height of twelve 

 or thirteen feet ; and in the south, near the sea coast, it 

 hardly rises a foot above the ground. In South America, 

 north of the equator, the most excitable Mimosas were 

 (next to Mimosa pudica), M. dormiens, M. somnians, 

 and M. somniculosa. Theophrastus (iv. 3) and Pliny 

 (xiii. 10) mention the irritability of the African sensitive 

 plant ; but I find the first description of the South Ameri- 

 can sensitive plants (Dormideras) in Herrera, Decad. II. lib. 

 iii. cap. 4. The plant first attracted the attention of the 

 Spaniards in 1518, in the savannahs on the isthmus near 

 Nombre de Dios : " parece como cosa sensible ;" and it was 

 said that the leaves ("de eelmra de una pluma de pajaros") 

 only contracted on being touched with the finger, and not 

 if touched with a piece of wood. In the small swamps 

 which surround the town of Mompox on the Magdalena, 

 we discovered a beautiful aquatic Mimosacea (Desmanthiis 

 lacustris). It is figured in our Plantes equinoxiales, T. i. 



