THE VEGETABLE WORLD. 347 



Still lighter, still less representative of the closed condi- 

 tion of woods, is the proper Palm-form where the social 

 kinds are grouped together. The real Palm-groves on the 

 northern border of Sahara and on the shores of the 

 Brazilian rivers, more resemble open columned halls with 

 perforated roofs ; and on the dry soil of the elevated plains 

 of Mexico the stems of the Yucca, Fourcroya and other 

 high-stemmed Liliaceous plants are collected in a very 

 peculiar way, affording neither shade from the sun nor 

 shelter from the wind. To these approach the deformed 

 masses of the Maguey-plants, with their broad, thick, rigid, 

 dull-green leaves, sharply toothed on their borders, and 

 their flowering stalks twenty feet high, rounded off into 

 strange, fantastic and impenetrable Bush by Cactuses of 

 manifold forms. 



The impenetrable Chapparals in the extensive plains 

 between the Nueces and the Rio Grande, formed of 

 Musquito-shrubs six to seven feet high, entwined with 

 Lianes ; the Palmetto-fields on the shores of the Sabine, 

 Natchez and other rivers of Texas, formed of Rush and 

 Dwarf Palms ; the low Acacia Bush of Australia Felix, and 

 lastly the wide jungles traversed by the elephants and tigers 

 in the East Indies, and formed of Bamboos and other lofty 

 Grasses, are all peculiarly characterized Formations of Bush, 

 which often not attaining the height of a man, or but little 

 exceeding it, do not all betray at the first glance the fre- 

 quently unsuperable obstacle they oppose to the intruder, 

 and even after Man has settled in the neighbourhood can 

 only be traversed by paths which the wild animals have 

 made. 



Change, by the movement it produces in sensation or 

 in the thoughts, is an important means to the awakening of 

 aesthetic pleasure or interest. The straight line is not 



