DISCREPANCIES. 



possession of the coral islets as soon as formed, in 

 the Pacific, is probably not quite correct; I fear it 

 destroys the poetry of this story, that feather- 

 and dirt-feeding, and parasitic insects and spiders 

 should be the first inhabitants of newly-formed 

 oceanic land."* 



The occurrence, far out on the boundless sea, of 

 creatures which we habitually associate with the 

 land, is a phenomenon which interests even those 

 w ho are little observant of natural history. Visits 

 of land-birds to ships have often been noticed by 

 voyagers, and that not of those species only which 

 are known to make long transmarine migrations, 

 but of small and feeble-winged races, such as 

 finches and warblers. It is much more remark- 

 able, however, to see insects under such circum- 

 stances; yet examples of this are not wanting. 

 Mr. Darwin expresses his surprise at finding a 

 considerable number of beetles, alive and appar- 

 ently little injured, swimming in the open sea, 

 seventeen miles off Cape Corrientes, at the mouth 

 of the La Plata. These may have been carried 

 down by a river, especially as several of them 

 were water-beetles ; but this will not account for 

 aerial insects taking a sea voyage. The same 

 naturalist was surrounded by flocks of butterflies 

 of several kinds, (chiefly of the genus CoJias,) ten 

 miles off the same coast. They were in countless 

 myriads, so that the seamen cried that it was 

 "snowing butterflies," extending as far as the eye 

 could range; and, even with a telescope, it was 

 not possible to see a space free from butterflies. 

 The day had been fine and calm, and so had the 

 day before; so that the supposition that the in- 

 sects had been involuntarily blown off the land 

 was inadmissible.! 

 * "Naturalist's Voy.," chap. i. t "Nat. Voy.," chap. vili. 

 85 



