The design of the caterpillars in rolling up the leaves is not only to conceal themselves from birds and predatory insects, but also to protect themselves from the cuckoo-flies, which lie in wait in every quarter to deposit their eggs in their bodies, that their progeny may devour them. Their mode of concealment, however, though it appear to be cunningly contrived and skilfully executed, is not always successful, their enemies often discovering their hiding place. We happened to see a remarkable instance of this last summer (1828), in a case of one of the lilac caterpillars which had changed into a chrysalis within the closely folded leaf. A small cuckoo-fly, aware, it should seem, of the very spot where the chrysalis lay within the leaf, was seen boring through it with her ovipositor, and introducing her eggs through the punctures thus made into the body of the dormant insect. We allowed her to lay all her eggs, about six in number, and then put the leaf under an inverted glass. In a few days the eggs of the cuckoo-fly were hatched, the grubs devoured the lilac chrysalis, and finally changed into pupae in a case of yellow silk, and into perfect insects like their parent.--_Library of Entertaining Knowledge_. The last extract, and all in the Library of Entertaining Knowledge signed J.R. are written by Mr. J. Rennie, whose initials must be familiar to every reader as attached to some of the most interesting papers in Mr. Loudon's Magazines. He is a nice observer of Nature, and one of the most popular writers on her phenomena. As we treated the cuts of the last portion of the "Library of Entertaining Knowledge," rather critically, we are happy to say that the engravings of insects in the present part make ample amends for all former imperfections in that branch of the work; some of the pupae, insects, their nests, &c. are admirably executed, and their selection is equally judicious and attractive. * * * * * SPIRITUOUS LIQUORS. Spirit-drinking appears to have attained a _pretty considerable_ pitch in America, where, according to the proceedings of the American Temperance Society, half as many tuns of domestic spirits are annually produced as of wheat and flour; and in the state of New York, in the year 1825, there were 2,264 grist-mills, and 1,129 distilleries of whiskey. In a communication to this society from Philadelphia, it is calculated, that out of 4,151 deaths in that city in the year 1825, 335 are attributed solely to the abuse of ardent spirits! * * * * * WOOD ENGRAVING. In early life Bewick cut a vignette for the Newcastle newspaper, from which it is calculated that more than _nine hundred thousand impressions_ have been worked off; yet the block is still in use, and not perceptibly impaired. * * * * * AUSTRIA.