CHAP. X. ] THE PALZARCTIC REGION. 211 
Mr. Wollaston; that those species which possess wings in 
Madeira, often have them rather larger than their allies in 
Europe. These two facts were connected by Mr. Darwin, who 
suggested that flying insects are much more exposed to be 
blown out to sea and lost, than those which do not fly (and Mr. 
Wollaston had himself supposed that the “stormy atmosphere’ 
of Madeira had something to do with the matter); so that the 
most frequent fliers would be continually weeded out, while the 
more sluggish individuals, who either could not or would not 
fly, remained to continue the race ; and this process going on from 
generation to generation, would, on the well-ascertained princi- 
ples of selection and abortion by disuse, in time lead to the 
entire loss of wings by those insects to whom wings were not a 
necessity. But those whose wings were essential to their exist- 
ence would be acted upon in another way. All these must fly 
to obtain their food or provide for their offspring, and those that 
flew best would be best able to battle with the storms, and keep 
themselves safe, and thus those with the longest and most 
powerful wings would be preserved. If however all the indi- 
viduals of the species were too weak on the wing to resist the 
storms, they would soon become extinct. 
Now this explanation of the facts is not only simple and 
probable in itself, but it also serves to explain in a remarkable 
manner some of the peculiarities and deficiencies of the Madeiran 
insect fauna, in harmony with the view (supported by the distri- 
bution of the birds and land shells, and in particular by the 
immigrant birds and insects of the Azores) that all the insects 
have been derived from the continent or from other islands, by 
1 A remarkable confirmation of this theory, is furnished in the Report to 
the Royal Society of the naturalist to the Kerguelen Island, “ Transit Expe- 
dition ””—the Rev. A. E. Eaton. Insects were assiduously collected, and it 
was found that almost all were either completely apterous, or had greatly 
abbreviated wings. The only moth found, several flies, and numerous beetles, 
were alike incapable of flight. As this island is subject to violent, and 
almost perpetual gales, even in the finest season, the meaning of the extra- 
ordinary loss of wings in almost all the insects, can, in this case, hardly be 
misunderstood. 
