80 THE BEAUTIES OF NATURE CHAP. 
not necessarily itself at rest; and yet we all 
know how it is refreshed by sleep. 
But though animals sleep, many of them 
are nocturnal in their habits. Humboldt gives 
a vivid description of night in a Brazilian 
forest. 
“Everything passed tranquilly till eleven 
at night, and then a noise so terrible arose in 
the neighbouring forest that it was almost 
impossible to close our eyes. Amid the cries 
of so many wild beasts howling at once the 
Indians discriminated such only as were (at 
intervals) heard separately. These were the 
little soft cries of the sapajous, the moans of 
the alouate apes, the howlings of the jaguar 
and couguar, the peccary and the sloth, and 
the cries of (many) birds. When the jaguars 
approached the skirt of the forest our dog, 
which till then had never ceased barking, 
began to how] and seek for shelter beneath our 
hammocks. Sometimes, after a long silence, 
the cry of the tiger came from the tops of the 
trees; and then it was followed by the sharp 
and long whistling of the monkeys, which 
appeared to flee from the danger which 
