The Visitor should not omit to inspect the Aviaries, of which there are several, in this end of the building. These contain Weaver Birds, Grenadiers, Grosbeaks, Mocking Birds, and Paroquets, most of them inhabitants of warm climates. There are also some Nightingales, whose rich song is frequently heard, even when the people crowd round them. The Weaver Birds, in the spring, may be seen constructing their curiously woven nests of grass, which hang from the branches like so many stockings; others of the feathered tribe build their habitations fearlessly in the presence of the visitor, with all the art of the basket-maker; here, indeed, bird-architecture of the most unique kind may be studied by the naturalist with delight and advantage. The Australian Paroquets have this spring again reared their young in these Aviaries with great success. It has been generally supposed that it was not possible to induce these birds to rear their young in this climate; but in 1856, the experiment was most successfully carried out in this Aviary. It has been repeated here since, each year; and in the present spring (1859), there are two healthy young birds which have been hatched in one nest, and there is promise of others. These observations more especially apply to the large species of Ground-paroquet (Platycercus hermalonotus), the smaller Shell-paroquet (Melopsittacus undulatus) having repeatedly bred in this country. Besides the birds mentioned, there are several of the British varieties, as well as some others of greater rarity or interest which may be specially mentioned. There are several Canaries which should be noticed, as they have been trapped in the Islands and forwarded direct, in their wild state. These must not, however, be confounded with those of the tame varieties in the same Aviary; they may be distinguished readily not only by the general carriage of the bird, but by their green plumage. The collection of Sparrows is also interesting: there are the common house and tree Sparrows of England (this last, however, is not to be confounded with the Hedge-sparrow), the Rice-sparrow of Java, and the Diamond-sparrow of Australia. The Diamond and Java Sparrows have successfully constructed nests; which is an additional evidence of how suitable the Tropical end of the Crystal Palace is for the Tropical birds. Here also are two or three specimens of the Californian Quail (Ortyx Californicus). These birds were brought from the Zoological Gardens at Antwerp. They breed freely, and are well adapted to thrive in a wild state in this climate, rearing from fifteen to twenty young ones in a brood; they are a great table delicacy, and it is probable at no distant period may enrich the list of British Game birds.