Owing to the combination of heat, moisture, and vegetation, the myriads of insects in Ceylon form one of the characteristic features of the island. In the solitude of the forests there is a perpetual music from their soothing and melodious hum, which frequently swells to a startling sound as the cicada trills his sonorous drum on the sunny bark of some tall tree. At morning the dew hangs in diamond drops on the threads and gossamer which the spiders suspend across every pathway; and above the pool dragon flies, of more than metallic lustre, flash in the early sunbeams. The earth teems with countless ants, which emerge from beneath its surface, or make their devious highways to ascend to their nests in the trees. Lustrous beetles, with their golden elytra, bask on the leaves, whilst minuter species dash through the air in circles, which the ear can follow by the booming of their tiny wings. Butterflies of large size and gorgeous colouring flutter over the endless expanse of flowers, and frequently the extraordinary sight presents itself of flights of these delicate creatures, generally of a white or pale yellow hue, apparently miles in breadth, and of such prodigious extension as to occupy hours, and even days, uninterruptedly in their passage--whence coming no one knows; wither going no one can tell.[1] As day declines, the moths issue from their retreats, the crickets add their shrill voices to swell the din; and when darkness descends, the eye is charmed with the millions of emerald lamps lighted up by the fire-flies amidst the surrounding gloom. [Footnote 1: The butterflies I have seen in these wonderful migrations in Ceylon were mostly _Callidryas Hilariæ, C. Alcmeone_, and _C. Pyranthe_, with straggling individuals of the genus _Euploea, E. Coras_, and _E. Prothoe_. Their passage took place in April and May, generally in a north-easterly direction.] No attempt has as yet been made to describe the class systematically, much less to enumerate the prodigious number of species which abound in every locality. Occasional observers have, from time to time, contributed notices of particular families to the Scientific Associations of Europe, but their papers remain undigested, and the time has not yet arrived for the preparation of an Entomology of the island. What Darwin remarks of the Coleoptera of Brazil is nearly as applicable to the same order of insects in Ceylon: "The number of minute and obscurely coloured beetles is exceedingly great; the cabinets of Europe can as yet, with partial exceptions, boast only of the larger species from tropical climates, and it is sufficient to disturb the composure of an entomologist to look forward to the future dimensions of a catalogue with any pretensions to completeness."[l] [Footnote 1: _Nat. Journal_, p. 39.]