GEOGRAPHICAL DISTRIBUTION OF PLANTS. 543 
If we ascend to the height of nine thousand feet above the sea on 
the Andes, and in the same latitude, tropical forms of vegetation 
almost entirely disappear. _ Those, on the contrary, which cha- 
racterise temperate climates, and even of the polar regions, become 
abundant. Large trees are no longer seen. Alder bushes, Bil- 
berries, Currants, Escallonia, with bitter and tonic leaves, of 
which this is the home; Hollies and Drymarias are bushes 
belonging to these regions, as well as the curious Calceolarias, 
with shoe-shaped corolla, the seeds of which have supplied horti- 
culture with an infinite number of varieties. Amongst the cha- 
racteristic families we also find Umbellifere, Caryophyllacee, 
Cruciferze, Cyperacexe, Mosses, and Lichens. Returning to more 
circumscribed vegetable districts, the climate of Caracas has often 
been called one of perpetual spring. A more delicious tempera- 
ture cannot be conceived. During the day it ranges between 
16° and 20° Cent., and in the night between 16° and 18°, with 
vegetative powers at once favourable to the growth of the Banana, 
the Orange, the Coffee shrub, the epi, oi is and Wheat. 
We must not quit th two beneficent 
trees—the Theobroma cacao and the Cow-tree. - The roasted and 
crushed seeds of Theobroma cacao, with the addition of sugar, make 
chocolate. Humboldt gives the following account of the Cow-tree, 
which has much of the bearing of Chrysophyllum ainito. “The fruit, ” 
Humboldt tells us, “is rather fleshy, consisting of one, sometimes 
two nuts. When incisions are made in the trunk an abundance 
of thick glutinous milk flows, which is without any acidity. This 
substance exhales a very agreeable balsam-like odour. It was 
presented to us in the rit of the Calabash-tree. We drank 
considerable quantities of it in the evening before going to bed, 
and again early in the morning, without experiencing any 
injurious effects. Negroes and fires people who work in the 
plantations drink of it, and soak their bread, maize, or tapioca in 
it. The master of the farm assured us that the slaves fattened 
visibly during the season when the Palo de Vacca furnishes them 
with most milk. Upon the arid flank of a rock,” adds Von 
Humboldt, “there grows a tree whose leaves are dry and coria- 
ceous, its great ligneous roots almost piercing the stone. During 
many months of the year not a shower waters its foliage, the 
