VEGETATION OF THE EITIEBA. 145 



Other plants which forcibly recall more tropical climates are 

 the so-called Aloes {Agave americana) and the Prickly Pears 

 (Opuntia Ficus-indica), which may be seen everywhere in the 

 neighbourhood of the villages rooted in the crevices of the driest 

 and most exposed rocks or forming impenetrable hedges for the 

 gardens. Though there is abundant evidence to show that these 

 plants had been introduced from Central America, they have here 

 completely acclimatized themselves, flowering and ripening their 

 fruit as if they had been truly natives. 



Among the most important introductions from more southern 

 latitudes are the Australian Eucalyptuses. The Eucalyptus glo- 

 bulus is planted round almost all the towns on the Riviera, and, 

 as it is of amazingly rapid growth, has already attained in many 

 places a great size. Though destitute of the graceful form of 

 many of our European trees, it is still a tree of striking and often 

 picturesque aspect. The foliage is of a glaucous tint, especially 

 in the broad amplexicaul leaves of the younger trees ; while the 

 long pointed or sickle-shaped leaves of the older trees, suspended 

 on slender petioles, and presenting their surfaces vertically to the 

 wind, tremble like the leaf of the aspen in the gentlest breeze, 

 and, though casting but little shade, impress us, like the murmur- 

 ing of running water, with a pleasant sense of coolness in the 

 sultry southern air. 



Notwithstanding, however, the vigorous growth of the Euca- 

 lyptus globulus, and its apparently complete adaptation to the 

 climate of the Riviera, there is still enough to keep us in mind of 

 the fact tliat it is an exotic ; for though the trees freely expand 

 in the spring their beautiful white tassel-like flowers, the seeds 

 do not ripen, and the cultivators find it necessary to import such 

 as may be capable of germination. 



Associated with the Eucalyptus is the beautiful Australian 

 Casuarina. The tree is destitute of leaves, but the branches emit 

 innumerable dark green pendulous shoots, jointed and striated 

 like the stems of an Equisetum. These give to it the general 

 aspect of a Conifer, and the whole tree impresses us by the grace- 

 ful symmetry of its form and the elegant plumose habit of its 

 singular pendulous ramification. Like the Eucalyptus it is of 

 very rapid growth. It has already attained in Provence a height 

 of some 30 or 40 feet ; and jvhen the wind rushes through 

 its branches, the long melancholy sigh with which the tree 

 responds is unlike the sound called forth by the same cause 



