106 
ARCANA ENTOMOLOGICA. 
cress, the similarity existing between which and some cruciferous 
plants has procured for it the name of the Nasturtium; while the 
Tinea flavella of Reaumur, the natural food of which is the Astra¬ 
galus glycyphyllus, in the absence of that, whatever variety may be 
presented to it, will feed only on some other leguminous plant.” 
Shortly previous to the publication of these observations I had 
made some remarks in Mr. Loudon’s Arboretum Britannicum, 
under the genus Quercus (p. 1815) nearly to the same effect. In 
making out the lists of the species of insects which attack our chief 
forest trees, I had noticed that although many are exclusively con¬ 
fined either to the oak, beech, birch, or hazel, yet many species 
feed indiscriminately upon any of these trees; some species of a 
genus vrould also be found to inhabit one of these kind of trees, and 
other species one or more of the other kinds; “ thus clearly proving 
not only the very natural character of the order Amentacese, but 
also the equally natural distribution of the insects themselves into 
genera consisting of species, all of which are either generally amen¬ 
taceous in their food, or are confined to the oak or the birch alone.” 
I am happy to find these observations confirmed and explained, 
believing as I do that the views here suggested are capable of a far 
wider extension than has yet been given to them. 
Insects observed at sea (see ante , p. 64).—“ 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. I lost some 
of the specimens, but those which I preserved belonged to the 
genera Colymbetes, Hydroporus, Hydrobius (two species), Notaphus, 
Synuchus, Adimonia, and Scarabseus. At first, I thought that these 
insects had been blown from the shore ; but on reflecting that out 
of the eight species, four were aquatic, and two others partly so in 
their habits, it appeared to me most probable that they were floated 
into the sea by a small stream which drains a lake near Cape Cor¬ 
rientes. On any supposition, it is an interesting circumstance to 
find insects, quite alive, swimming in the open ocean, seventeen 
miles from the nearest point of land. There are several accounts 
of insects having been blown off the Patagonian shore. Captain 
Cook observed it, as did more lately Captain King, in the Adven¬ 
ture. The cause probably is due to the want of shelter, both of 
trees and hills, so that an insect on the wing, with an off-shore 
