222 Vegetable Cows. 
celebrated traveller Humboldt. This tree forms extensive forests 
on the mountains near the town of Coriaco, and elsewhere along 
the sea coast of Venezuela—growing to upwards of one hundred 
feet in height, with a trunk six or eight feet in diameter, and 
branchless for the first sixty or seventy feet of its height. It is 
popularly known as the cow tree, Palo de Vaca, or Arbol de 
Leche. ‘Its milk, which is obtained by making incisions in the 
trunk, so closely resembles the milk of the cow, both in appear- 
ance and quality, that it is commonly used as an article of food by 
the inhabitants of the places where the tree is abundant. Unlike 
many other vegetable milks, it is perfectly wholesome and very 
nourishing, possessing an agreeable taste, like that of sweet cream, 
and a pleasant balsamic odour, its only unpleasant quality being a 
slight amount of stickiness. | ‘The chemicai analysis of this milk 
has shown it to possess a composition closely resembling some 
animal substances, and, like animal milk, it quickly forms a yellow, 
cheesy scum upon its surface, and, after a few days’ exposure to 
the atmosphere, turns sour and putrifies. It contains upwards of 
thirty per cent. of a resinous substance called ga/actin by chemists.” 
(Treas. of Botany.) Speaking of this tree, Humboldt says :— 
“They (the natives) profess to recognise, from the colour and 
thickness of the foliage, the trunks that yield the most juice, as 
the herdsman distinguishes, from external signs, a good milch 
cow. Amidst the great number of curious phenomena that I 
have observed in the course of my travels, I confess there are 
few that have made so powerful an impression on me as the 
aspect of the cow tree. A few drops of vegetable juice recall to 
our minds all the powerfulness and fecundity of nature. On the 
barren flank of a rock grows a tree with coriaceous and dry 
leaves. Its large woody roots can scarcely penetrate into the 
stone. For several months in the year, not a single shower 
moistens its foliage. Its branches appear dead and dried, but 
when the trunk is pierced, there flows from it a sweet and nourish- 
ing milk. It is at the rising of the sun that this vegetable 
fountain is most abundant. The negroes and natives are then 
seen hastening from all quarters, furnished with large bowls to 
receive the milk, which grows yellow and thickens at the surface. 
Some empty the bowls under the tree itself, others carry the juice 
home to their children.” 
In the Dogbane order, the Afocynacee, which includes plants 
that are mostly of a venomous nature and possess an exceedingly 
acrid and drastic juice, we have a second example of a tree that 
secretes a wholesome, milk-like fluid. This is the Zabernemon- 
tana utilis, the cow tree of Demerara, or hya-hya of the natives. 
This tree grows in abundance in the forests of British Guiana, and 
its bark, when tapped, yields a copious supply of thick, sweet 
