ON VEGETABLE GARDENING. 207 



but the same pre-eminence in garden cultivation does 

 not now appear which was claimed for her by Colu- 

 ntiella in the time of the Roman republic, and which 

 was probably as well deserved during the dominion of 

 the Moors. The oldest and most extensive gardens 

 now to be found in Spain are of Moorish origin, and 

 have once been appendages to the palaces of their 

 Arabian kings. 



The Chinampas, or floating gardens of Mexico, are 

 justly considered objects of the greatest curiosity. 

 The invention of these gardens is said to have arisen 

 out of the extraordinary situation in which the Aztecs 

 were placed on the conquest of their country by the 

 Tepanecan nation, when they were confined in great 

 numbers to the small islands on the lake, and were 

 driven to exercise all manner of ingenuity in order to 

 provide a sufficiency of food for their sustenance. 

 Humboldt conjectures that the first idea of these float- 

 ing gardens may have been suggested by nature 

 herself, seeing that, ' on the marshy banks of the 

 lakes of Xochimilco and Chalco the agitated waters, 

 in the time of the great floods, carry away pieces of 

 earth covered with herbs and bound together with 

 roots. The first Chinampas were mostly fragments 

 of ground artificially joined together and cultivated.' 

 Following up this suggestion, it would not be difficult, 

 by means of wicker-work formed with marine plants 

 and a substratum of bushes combined with tenacious 

 earth or clay, to construct similar gardens of adequate 

 dimensions. Upon these was placed fine black mould 

 sufficiently deep for the sustenance of the plants which 

 it was desired to raise. The form usually given to 

 these Chinampas was quadrangular, and their size 

 varied from one hundred and fifty to three hundred 

 feet in length, with a breadth of from twenty to se- 

 venty feet. 



At first the use of these floating gardens was con- 

 fined to the growth of maize and other objects of 



