304 SCIENTIFIC ILLUSTRATIONS [Ret 



cause it is heard during the day and the ostrich's during the 

 night D. 



The Instinct of Rest. 



All creation seems to possess the instinct of rest. "We well 

 know how eagerly the human heart sighs for rest. But it is not 

 so well known that even plants sleep. Their strange sleep, says 

 Figuier, vaguely recalls to us the sleep of animals. In its sleep 

 the leaf seems by its disposition to approach the age of infancy. 

 It folds itself up, nearly as it lay folded in the bud before it 

 opened, when it slept the lethargic sleep of winter, sheltered 

 under the robust and hardy scales, or shut up in its warm down. 

 We may say that the plant seeks every night to resume the 

 position which it occupied in its early days, just as the animal 

 rolls itself up, lying as if it lay in its mother's bosom. All the 

 world seems to express the sentiment contained in the words 

 uttered by one of old, who desired the wings of a dove in order 

 to seek and obtain rest. v. 



A Limited Retaliation. 



Camels have a great share of intelligence, and the Arabs 

 assert that they are so extremely sensible of injustice and ill- 

 treatment that, when this is carried too far, the inflictor will 

 not find it easy to escape their vengeance, and that they will 

 retain the remembrance of an injury till an opportunity offers 

 for gratifying their revenge. Eager, however, to express their 

 resentment, they no longer retain any rancour when once they 

 are satisfied ; and it is even sufficient for them to believe they 

 have satisfied their vengeance. Accordingly, when an Arab has 

 excited the rage of a camel, he throws down his garments in 

 some place near which the animal is to pass, and disposes them 

 in such a manner that they appear to cover a man sleeping under 

 them. The animal recognises the clothes, seizes them in his 

 teeth, shakes them with violence, and tramples on them in a 

 rage. When his anger is appeased he leaves them, and then 

 the owner of the garments may make his appearance, and with- 

 out any fear may load and guide him as he pleases. P. 



