THE CACTUS TRIBE. 219 



Gooseberry bushes, are used by our country people to form 

 hedges to their gardens, are the Opuntias in Mexico, on 

 the west coast of South America and in the southern part 

 of Europe, and with greater success in the Canaries ; their 

 firm, shapeless branches soon interweave themselves into 

 an impenetrable barrier, opposing, by their dreadful spines, 

 an insuperable obstacle to the intruder. Lastly, the 

 medicine -chest does not go away empty, for the physicians 

 of America make abundant use of the acid juice for fomen- 

 tations in inflammations, and give the boiled fruit in affec- 

 tions of the chest ; not to mention some other prescriptions. 

 In the same way that grass and clover are not 

 immediately valuable to man, but serve as food for useful 

 animals, so is it with a number of Cacti, which support 

 an insect of extraordinary importance. This is the 

 Cochineal insect ( Coccus CactiJ, a little, very insignificant 

 creature, externally just like the little, white, cottony 

 parasite, which is so often found upon the plants in 

 our hot-houses, and yet, through the invaluable colouring 

 matter it contains, so infinitely different from it. Formerly 

 the culture of Cochineal was confined to Mexico alone, 

 and the Government took great care to keep it secret. In 

 the year 1725, there were animated debates in Europe, as 

 to whether the Cochineal was an insect or the seed of a plant. 

 Thierry de Menonville carried it, at the peril of his life, to 

 the French colony of St. Domingo, in 1785. It was also 

 introduced into the Canaries, through Berthelot, in 1827. 

 In recent times, successful experiments in its culture have 

 been made even in Corsica and in Spain. But although it 

 is now abundantly raised in Brazil and the East Indies, 

 Mexico still produces the greatest quantity and the finest 

 kind. According to Alexander von Humboldt* the export of 



* Essai politique sur la nouvelle Espagne, Vol. in. 



