6 Teneriffe. [Jan., 
white milky juice, which is very acrid and caustic ; when inspissated 
it is employed imstead of cantharides by the natives, formerly it was 
used considerably in England as a cathartic, emetic, errhine, and 
rubefacient when properly diluted, but its internal use is now 
discontinued in medicine. At the upper part of this zone, immense 
plants of the Cacalia Kleinii thrive with much luxuriance. That 
extraordinary tree the dragon tree (Dracena draco) grows only 
in this zone; it produces a fine scarlet gum, called by the old 
Arabian physicians “dragon’s blood.” In a garden in the Villa de 
Orotava 1s a renowned dragon tree, supposed to be many thousand 
years old: when the Spaniards arrived at Orotava in 1493 the 
trunk was then hollow. It is about 60 feet high and 49 in cir- 
cumference near the ground, and 354 feet at 6 feet from the surface. 
Humboldt made it only 45 feet in circumference, but he must have 
measured it higher up; I once cleared the ground round the trunk 
and found it 494 feet. Many years ago a large arm was blown 
down by a storm; the present proprietor has very properly taken 
measures to preserve the tree, by supporting it with props and 
masonry. 
During many centuries this zone gave employment to the greatest 
part of the population of the island in the cultivation of the vine, 
but some years ago the grapes became diseased, which produced much 
distress among the poor; fortunately, they took to cultivating the 
cochineal insect on the Cactus cochinellifera and Opuntia vulgaris. 
It was raised with great success on the south side of the island, 
whose arid and parched surface appeared at first to be particularly 
favourable to it, as it yielded occasionally a profit of 45/. per acre; 
but it proved a very precarious industry, for although the female 
insect prefers a high temperature, yet it is killed by a high radi- 
ation. Fortunately, the vines have recovered from their disease, 
and the cochineal trade has fallen off in importance. 
The second zone of plants, extending from 2,000 to 3,400 feet 
above the sea, may be properly called the region of laurels; by 
the natives it is termed “ Alta Verde,’— Green Mount. ‘This 
region exhibits thick woods of Canarian oak (Quercus Canariensis), 
Laurus nobilis, L. indica, and L. foetens, two sorts of chestnut trees, 
a wild olive (Olea excelsa), some heaths, such as the Erica arborea 
and H. scoparia; masses of daphne, yellow St. John’s wort, some 
species of the Sideroxylon, several trees of the myrtle species, round 
which was entwined the Canarian ivy (Hedera Canariensis), There 
is found in great abundance in this zone, as well as at an elevation 
of more than 9,000 feet, a very beautiful leguminous plant, called 
by the natives “ Codeso” (Codonocarpus frankenotdes) ; it has com- 
posite leaves of a light-green colour, a woody stem, and branches 
out like a tree; it makes an excellent fire for the traveller, and 
when burnt, gives out a strong aromatic smell. In the lower 
