Hence we cannot suppose that the insects were blown off the land, but we must conclude that they voluntarily took flight.

The great bands of the Colias seem at first to afford an instance like those on record of the migrations of another butterfly, Vanessa cardui (8/5.

Lyell's "Principles of Geology" volume 3 page 63.); but the presence of other insects makes the case distinct, and even less intelligible.

Before sunset a strong breeze sprung up from the north, and this must have caused tens of thousands of the butterflies and other insects to have perished.
On another occasion, when seventeen miles off Cape Corrientes, I had a net overboard to catch pelagic animals.

Upon drawing it up, to my surprise I found a considerable number of beetles in it, and although in the open sea, they did not appear much injured by the salt water.