greatest attention, by remarking that, though the processes could be seen and their progress traced, the modus operandi was not traceable.  Yet the observer could not fail to be impressed with the perfect concurrent adaptation of these organisms to the circumstances of their being; they were subject to no caprices, their life-cycles were as perfect as those of a crustacean or a bird, and while the action of the various processes was certain, their rapidity of increase and the shortness of their life history were such that they afforded a splendid opportunity of testing the correctness of the Darwinian law.

* * * * *

WINTER AND THE INSECTS.

For a number of years previous to 1878 we had in Pembroke but little or no severe cold, owing to the prevalence of southeast, south, west, and especially southwest winds.  In many places, fuchsias that were left in the ground for the entire year had not been frozen to the root within the memory of man.  Some of these plants had grown to be trees five or six yards in height, and with a trunk the size of one’s leg.  Now, during the same series of years, many insects that are common throughout the rest of Great Britain did not cease to be rare with us, or rather were confined to certain circumscribed limits.  Thus, the Noctuellae, with the exception of a few species abundant everywhere, were almost wanting, and I know of no other country where the dearth of common species of nocturnal butterflies was so great.  But during the winter of 1878 there supervened a radical change.  Persistent winds from the northwest, driving back the currents of warm air from the south, brought on an intense cold that froze everything; or, when some variation occurred in them, clouds formed and dissolved into a rain that immediately froze, so that the large roads remained for weeks covered with a layer of rime from two to four inches thick.

[Illustration:  GREEN WOODPECKER SEARCHING FOR INSECTS.]

The winters of 1879 and 1880 were equally cold; we may even say that the latter was the severest that had been experienced in fifty years.  This year the sea-sand, along with the ice and snow, formed a thick crust all along the tide-line—­this being something rarely seen along our coast.  The first of these three winters (1878-1879) killed all the arborescent veronicas and a few sumacs.  As for the fuchsias and myrtles, they were frozen down to the level of the soil.

I now come to the effects of this severe cold upon the insects.

The Lepidoptera, which before were rare, became more and more common in 1879, 1880, and 1881, and so much so that during the last named year they abounded; and species that had formerly been detected only at certain favored points spread over the entire coast and into the interior of the country.  The geometers appeared in numbers that were unheard of.  But this change was especially striking as regards the Noctuellae, in view of the previous rarity of the individuals belonging to this family.