THE WARMER TEMPERATE ZONE. 99 



We cannot omit to mention a species of the Cactus tribe, 

 called (somewhat inappropriately) the Indian Pig (Opuntia 

 Ficus-Indica), which lives where few other plants could 

 exist, on Mount Etna, that is to say, and its volcanic 

 fields, but it is the nature of this tribe to be fond of hot, 

 dry, rocky places. This kind of Cactus is employed by the 

 Sicilians, as we learn from Professor Lindley, to render 

 such desolate regions susceptible of cultivation. " It readily 

 strikes into the fissures of the lava, and soon, by extending 

 the ramifications of its roots into every crevice of the stone, 

 and bursting the largest blocks asunder by their gradual 

 increase, makes it capable of being worked." 



These are foreign sights to English eyes ; but far more 

 foreign-looking is the vegetation in some parts of Spain. In 

 that land of stagnation, where the pristine beauty of nature is 

 still undisturbed and uninjured by railways and other modern 

 improvements, we may not only feast our eyes on the golden 

 glory of the Orange-groves for the Oranges are naturalized 

 there but we may wander in splendid groves of Gum Cistus 

 (said to be almost peculiar to the South of Spain and Por- 

 tugal), in which are intermingled tree-like Heaths, adorned 

 with a profusion of gay flowers; and more than this, we 

 here for the first time make acquaintance with "several 



