singularly applicable to modern society--called the Howler after the word _Mycetias_, an earthquake with a hollow bellowing noise. The word is from μύζω (to moan). An old writer (Margrave) wrote in his Natural History of Brazil, in 1648, that all the Howlers assembled in the morning and evening in the woods, and that one takes his place on a tree high up, and motions to his companions to sit down and listen, and then, after having seen them all seated, commences his discourse, pitched at so high a key that at a distance one would imagine that all the congregation were joining in. But this is not the case; only one orator is allowed to speak at a time, and all the rest wait politely, but not very patiently. When he has had enough howling he motions to the whole, who burst out into a fine chorus for some time. Then, by order, they all cease, and the first recommences, and after having been listened to with due attention the whole depart. What the noise must be sometimes, if they all join in, may be gleaned from the fact that Humboldt saw the trees crammed with them, and believed that more than 2,000 may be found in a square league. It really does occur that when there is an assemblage of these Monkeys--for instance, of the _Mycetes Caraya_--when the weather is warm and open, they make the forests resound in the morning and evening with their overwhelming voices. The males begin the dreadful concert, in which the females, with their less powerful voices, sometimes join, and which is often continued for several hours. It does not appear that any especial cause induces them to begin their noise, and probably they do it because it pleases them, as the birds do in their prolonged songs. Mr. Darwin suggests very forcibly that the females are pleased or attracted by it, liking (as in higher animals) the loudest and most intolerable of the noise-makers best. Hence one Howler is, of course, always trying to outdo the others. But it is true that some Howlers live in pairs and indulge in their vocation all the same. Wallace, however, states that the females do not join in the noise, and that the howling is made before bad weather, and in the evening. These Howlers are the largest of the Monkeys of the New World, some being nearly three feet in length, without counting the long prehensile tail; they have movable thumbs on their hands, a hairless space underneath the tip of the wonderful tail, and the howling apparatus in the throat. They have rather tall heads, with beard and large lower jaws, which, with a thickness about the throat, give the appearance of an unusual swelling being there, the cause of which will be noticed further on. Some have long and others short fur, but generally there is much of it about the head (where it is brushed forwards) and neck. Black and red are favourite colours, and the young of both sexes differ often in their tints from the adults, and so do the males from the females. One kind in particular is decidedly coloured.