"And now," said Miss Harson, "the last of these useful trees--the cow tree, or milk tree--is the most curious one of all. Like the caoutchouc, it is a native of South America; but the sap is a rich fluid that answers for food, like milk. It is a fine-looking tree with oblong, pointed leaves about ten inches in length and a fleshy fruit containing one or two nuts. The sap is the most valuable part; and when incisions are made in the trunk of the tree, there is an abundant flow of thick milk-like sap, which is described as having an agreeable and balmv smell. The German traveler Humboldt drank it from the shell of a calabash, and the natives dip their bread of maize or cassava in it. This milk is said to be very fattening; and when exposed to the air, it thickens into a substance which the people call cheese."