NATURE IN MOTION. 79 



by hunger or fierce enemies; they have even been sus- 

 pected of passing through a tunnel under the straits of 

 Gibraltar, from Africa, to Europe. Their mode of crossing 

 rivers is a beautiful evidence of their ingenuity and in- 

 stinct. A powerful male seizes a branch that projects 

 over the baks of the stream, and suspends himself by 

 his prehensile tail ; another takes hold of him, and so on 

 until they have a row as long as the river is wide. Then 

 they begin to swing the living chain, and continue until 

 the impetus is powerful enough to enable the last one 

 to take hold of a tree on the opposite shore. Over this 

 strange bridge the whole host passes safely ; as soon as 

 they are across, the first monkey lets go his hold, the 

 chain swings again, and so they all safely get over large 

 rivers. 



The so-called domestic animals travel exclusively by the 

 agency of man, and in his company. It is thus that the 

 horse, a native of the wide steppes of Central Asia, which 

 was not known on this continent before the arrival of the 

 Spaniards, now roams over it in vast herds from Hud- 

 son's Bay to Cape Horn. To man we owe it, that the 

 goat climbs our Eocky Mountains, and white, woolly sheep 

 graze on scanty hill-sides, whilst the heavier, slower cattle 

 fatten on rich low grounds, and remind us, in the far 

 backwoods, by the sweet harmonies of their bells, of the 

 neighborhood of men. But here, also, the weeds have come 

 with the good plants. Thus the domestic (!) rat, a native 

 of the Old World, was carried in ships to the Cape, to 

 Mauritius and Bourbon, to the Antilles and Bermuda. An 

 Antwerp ship brought them, 1544, first, to this continent. 



