Charles Morris, Home Life in All Lands—Book III—Animal Friends and Helpers
“ When we talk of the house dog and cat, the horse and cow, it must be remembered [260] that each of these is a single species of animal. But when we talk of the monkey we have to do with a whole family of animals, of a great many different species.Thus there are New World monkeys and Old World monkeys which differ so that we can always tell them apart. One curious thing about the New World monkeys is that they all live in trees and have long tails, which they can use in such a way that they seem to have five legs. ”
