DISCREPANCIES. 



not succeed in capturing it. These are facts re- 

 lated by entomologists who could not have mis- 

 taken the objects observed, and consequently they 

 are entitled to full credit. They are full of interest 

 in relation to a subject of physiological discussion, 

 the power of flight supposed to be possessed 

 by these, our little favourites, and the speed 

 with which they are conveyed across the ocean, 

 whether by an actual expenditure of muscular 

 energy, or whether carried by the force of the 

 wind alone. My own opinion certainly is, that 

 the amount of muscular power exerted during 

 flight is trifling, compared with what we have 

 usually supposed it to be, and that in these in- 

 stances the insects have been greatly aided in their 

 progress by the wind. The speed at which they 

 must have traversed the ocean seems to confirm 

 this view; as it is well known that the ^Eshna 

 will not live more than a few days, if unable to 

 obtain its living food." 



The Atlantic being the great highway of na- 

 tions, we have more abundant observations on 

 this than on other oceans, but similar phenomena 

 exist elsewhere. Humboldt mentions having seen, 

 in the Pacific, at a vast distance from the coast, 

 large- winged Lepidopteni (butterflies) fall on the 

 deck of the ship. 



Equally striking is the presence of winged insects 

 at very lofty elevations. Saussure found butter- 

 flies at the summit of Mont Blanc, and Ramond 

 observed them in the solitudes around that of 

 Mont Perdu. Captain Fremont saw honey-bees 



neither from the Cape de Verd Isles nor the Antilles, but from 

 the continent of South America, to which the genus Morpho 

 is limited. The nearest part of that continent is not less than 

 one thousand Ave hundred miles from the position of the ob- 

 server. 



87 



