At this season of the year any thing relating to birds and insects can not fail to prove interesting, more especially when it is borne in mind that their economical relations to each other are becoming better recognized and appreciated. We therefore append here the following extract sent us by our Nazareth correspondent, elsewhere alluded to. It is in a very condensed form, and contains many valuable facts.

"At the late agricultural meeting at St. Gallen, in Switzerland, Baron von Tschudi, the celebrated Swiss naturalist, dwelt on the important services of birds in the destruction of insects. Without birds, said he, no agriculture and vegeta-tion are possible. They accomplish in a few months the profitable work of de-struction which millions of human hands could not do half so well in as many years; and the sage therefore blamed, in very severe terms, the foolish practice of shooting and destroying birds, which prevails more especially in Italy, recom- mending, on the contrary, the process of alluring birds into gardens and corn-fields.

"Among the most deserving birds he counts swallows, finches, titmice, redtails, etc. The naturalist then cites numerous instances in support of his assertion. In a flower-garden of one of his neighbors, three tall rose-trees had suddenly been covered with about 2,000 tree-lice. At his recommendation a marsh-titmouse was located in the garden, which in a few hours consumed the whole brood, and left : the roses perfectly clean. A redtail in a room was observed to catch about 900 flies in an hour. A couple of night-swallows have been known to destroy a whole swarm of gnats in fifteen minutes. A pair of golden-crested wrens carry insects as food to their nestlings upon an average thirty-six times in an hour. For the protection of orchards and woods, titmice are of invaluable service. They cou-sume, in particular, the eggs of the dangerous pine-spiders. One single female of such spiders frequently lays from 600 to 800 eggs, twice in the summer season, while a titmouse with her young ones consume daily several thousands of them. Wrens, nuthatches, and woodpeckers often dexterously fetch from the crevices of tree-bark numbers of insects for their nestlings.

In 1848 an immense swarm of caterpillars, of the well-known genus Bombax dispar, had destroyed all i the tree leaves in the orchard of Count Casimus Wadzibi, who observed the stems and branches coated, as it were, with a heavy crust of millions of eggs, surrounded by a hairy skin. He employed scores of hands to scrape them off, but to no avail, and the trees were about to decay. Luckily, towards the winter, numerous flights of titmice and wrens frequented that part, and it was soon perceived that the nests of the caterpillars were visibly diminishing. In the spring time about twenty pairs of titmice made their nests in the garden, and in the course of the summer they had cleared the trees of all the caterpillars.

"M. Tschudi considers sparrows to be very useful birds, as one single pair usually carry to their nest every day about 300 caterpillars, an advantage that amply compensates for the cherries the birds steal in the garden. Owls also consume, morning and evening, vast numbers of wood insects. Some species of birds, such as starlings, jackdaws, rooks, jays, and speckled magpies, are distinguished for destroying maybugs or cockchafers. White, of Selborne, who devoted some time to the observation of the movements of a pair of common barn owls, found; among other things, that they often carried to their nest a mouse every five minutes; while another pair of great owls had carried to their nest in one evening in June no less than eleven mice. Most of the smaller birds feed, either entirely or partially, especially during the hatching season, on insects, worms, snails, spiders, etc.; so do also the hedge-sparrows, woodpeckers, thrushes, fly-catchers, (Muscicapas,) wagtails, larks, etc.

"Without these useful birds, obnoxious insects would increase in such masses as to become a permanent plague in Europe, and destroy all fruit and vegetation, like the locusts in the East; and the farmer, in balancing the gain and loss accruing from these useful birds, ought to consider the latter in the light of domestic servants, whose cost of keeping is amply repaid by their services".