NATURAL HISTORY OF THE BERMUDAS. 323 



my small collection of Bermuda Lepidoptera, asked for, and 

 obtained my, permission to take it to the British Museum. 

 From the examination there made I learned for the first 

 time that my unknown specimens were the American 

 Butterfly (Terms /isa). I was still in the dark, however, 

 with regard to their sudden appearance, never dreaming it 

 to be possible they could have crossed the ocean to the 

 Bermudas. 



Mr. Jones's account of the more recent visitation has, 

 however, thrown so strong a light upon that of 1847, as to 

 render it impossible to doubt that both events are due to 

 one and the same cause. 



Bermuda being composed of comminuted sea-shell, from 

 the surrounding surf-beaten reefs of coral, washed up by the 

 waves, and driven by the wind into its present form of hills 

 and dales, there must have been a period when terrestrial 

 vegetation had no existence therein, and when its fauna 

 was limited to the myriads of sea birds, which occupied and 

 bred upon its shores. It is to the deposit formed by these 

 birds in centuries of the past that the islands are indebted 

 for their surface soil. 



When discovered by Bermudez, in 1515, the islands were 

 covered by a growth of cedar and other trees, the seeds of 

 which had, unquestionably, been floated from the shores of 

 America, together with those of various plants. Vegetation 

 must, therefore, have preceded the advent, or rather the 

 establishment of land birds and insect formations, other- 

 wise they could not have supported life. 



Hence we may infer that, in times far beyond the reach 

 of history, the native species of Lepidoptera now found in 

 the Bermudas, or the greater portion of them, were intro- 

 duced from America by the same natural causes which con- 

 veyed the great flight of Terias /isa to those islands in 

 October, 1874. 



