It is not as often recognized by naturalists, as it might be, that any living thing will change its habits when it becomes its interest to do so. Insects generally have preference for some particular species of plant, and are often so associated therewith that naturalists are incredulous when told of a certain species attacking other things. Yet we know how the Colorado potato beetle has taken to Solanum tuberosum when the stock of Solanum rostratum failed, and surely numerous such instances must be common. While in the Iron Mountains in Tennessee recently, the writer saw a species of Scutellaria which had every leaf skeletonized precisely as the elm is. Looking for the insect, he found what appeared to him to be a species of Galereuca, closely resembling the elm beetle. Not considering himself an entomologist, he mentioned his suspicions to a distinguished student in that branch of science, but was told " it was impossible it could be that beetle, as it fed only on the elm." Yet it seems unlikely any insect would starve. If some found themselves in a region like this, where there were no elms, why should they not look up something else to feed on? That there is a change of habit continually going on in animated nature is beyond question.

Besides the case of the potato beetle, we often see it in birds. There were no chimneys in America once for swallows to build in, and the English sparrow is another illustration.

In the Country Gentleman of Aug. 12th, a correspondent says: -

"The English Sparrow will not build in the foliage of trees, as most birds do, but quite often builds in holes in old trees. A dead tree is preferred, but they will build in a hole in a large tree, even though full of foliage. I have often, when a boy, found several nests in an old tree. Ivy seems to be their especial delight for an abode, and to breed in. Many houses overgrown with ivy, seem literally alive with sparrows".

This is true enough of the sparrow in England but it is not true if the "will not" is intended to mean " under any circumstances." In the public squares of Philadelphia, they have taken to building in the foliage of the trees. There are thousands of these nests through the city squares. They make fearful bungles of nest building it is true. They use as much straw to make one nest as other birds do to make a dozen, and so ungainly, too! They look like huge wisps of straw stuffed into a crotch after having been used to wipe a pair of muddy boots.

The changes going on in nature are wonderful. Not only changes in .habit, but changes in form and changes in every character. The man who believes that everything in the world has remained just as it was in the beginning, scarcely uses his eyes as he might do.