DISTRIBUTION OF ANIMALS. 593 



these animals would doubtless have been more strong and active, and might, when hard 

 pressed, have performed a much longer voyage. Hence islands remote from the con- 

 tinent may obtain inhabitants by casualties which, like the late storms in Morayshire, 

 may only occur once in many centuries, or thousands of years, under all the same cir- 

 cumstances." The isles of the Pacific have no quadrupeds, but some of those just 

 mentioned hogs, dogs, and rats, with the exception of a few bats; and only rats are 

 found in Easter Island, the most remotely seated in the Pacific. 



There is another method of transport, which, though very rarely in action, may exten- 

 sively diffuse both vegetable and animal tribes. In a former chapter of this work, the 

 occurrence of floating islands in lakes has been noticed ; and in addition to the instances 

 there referred to, Mr. Darwin describes some on the Lake of Tagua-cagua, in Chili, 

 which deserve attention. " They are composed of the stalks of various dead plants 

 intertwined together, and on the surface of which other living ones take root. Their 

 form is generally circular, and their thickness from four to six feet, of which the greater 

 part is immersed in the water. As the wind blows they pass from one side of the lake to 

 the other, and often carry cattle and horses as passengers." Towards the mouth of the 

 great rivers, the Mississippi, Amazon, Orinoco, Congo, and Ganges, similar islands are 

 formed, where any obstacle occurs to the further progress of the wood and vegetation 

 drifted down by the currents from the interior countries, and sometimes these islands are 

 driven from their moorings by a flood or a storm, and then float away, either entire or in 

 piecemeal, into the open sea. They have been several times met with in the Indian 

 Ocean, after the typhoon has raged, covered with mangrove-trees interwoven with under- 

 wood, and ships have sometimes been in peril, in consequence of mistaking them for 

 firm ground. " It is highly interesting to trace, in imagination, the effects of the passage 

 of these rafts from the mouth of a large river to some archipelago, such as those in the 

 South Pacific, raised from the deep, in comparatively modern times, by the operations of 

 the volcano and the earthquake, and the joint labours of coral animals and testacea. If a 

 storm arise, and the frail vessel be wrecked, still many a bird and insect may succeed in 

 gaining by flight some island of the newly formed group, while the seeds and berries of 

 herbs and shrubs, which fall into the waves, may be thrown upon the strand. But if the 

 surface of the deep be calm, and the rafts are carried along by a current, or wafted by 

 some slight breath of air fanning the foliage of the green trees, it may arrive, after a 

 passage of several weeks, at the bay of an island, into which its plants and animals may 

 be poured out as from an ark, and thus a colony of several hundred new species may at 

 once be naturalised." Extremely rare as is the occurrence of such a wandering Delos, it 

 unquestionably belongs to the class of facts, romantic as it appears ; nor do the effects 

 attributed to it at all trespass beyond the sobrieties of calculation. If the West India 

 islands had no samples of animal nor vegetable life common to the continent of North 

 America, their reception of both might be presumed, whenever the great raft of the 

 Atchafalaga (an arm of the Mississippi, ten miles long, and two hundred yards broad,) is 

 broken up, as it is almost certain to be, sending down a hundred islets to float in the 

 waters of the Gulf of Mexico. 



The' theory embraced with reference to animal distribution may appear to some 

 readers at variance with the authority of Revelation, which, according to popular inter- 

 pretation, teaches the collection of types of all living races into the Noachian ark, the 

 occurrence of a universal deluge destroying the other members of each family, and the 

 subsequent dispersion of the preserved stock from one common centre, the mountains of 

 Ararat, to repopulate the world. With this theory of Linnaeus and Pennant it is impos- 

 sible to reconcile zoological facts, without supposing a series of the most astounding and 

 useless miracles, concerning which a total silence is preserved in the Scripture narrative. 



Q Q 



