The Malay archipelago : the land of the orang-utan ... - Wallace Online

XXXIX.] NATURAL HISTORY OF THE PAPUAN ISLANDS. 443to land, and from land to sea, has taken place not once or twiceonly, but again and again, during countless ages of past time.Now the study of the distribution of animal life uj^on thepresent surface of the earth causes us to look upon this constantinterchange of land and sea— this making and unmakingof continents, this elevation and disappearance of islands—asa potent reality, which has always and everywhere been in progress,and has been the main agent in determining the mannerin which living things are now grouped and scattered over theearth's surface. And when we continually come ujoon suchlittle anomalies of distribution as tliat just now described, wefind the only i-ational explanation of them in those repeatedelevations and depressions which have left their record inmysterious, but still intelligible characters on the face oforganic nature.The insects of New Guinea are less known than the birds,but they seem almost equally remarkable for fine forms andbrilliant colours. The magnificent green and yellow Ornithopterseare abundant, and bave most probably spread westwardfrom this point as far as India. Among the smaller butterfliesare several peculiar genera of Nymphalidte and Lyc^nidfe, remarkablefor their large size, singular markings, or brilliantcoloration. The largest and most beautiful of the clear-wingedmoths (Cocytia d'urvillei) is found here, as well as the large andhandsome green moth (Nyctalemon orontes). The beetlesfurnish us with many si^ecies of large size, and of the mostbrilliant metallic lustre, among which the Tmesisternus mirabilis,a longicorn beetle of a golden green colour ; the excessivelybrilliant rose-chafers, Lomaptera wallacei and Anacamptorhinafulgida ; one of the handsomest of the Buprestidaj,Calodema wallacei ; and several fine blue weevils of the genusEupholus, are perhaps the most conspicuous. Almost all theother orders furnish us with large or extraordinary forms. Thecurious horned flies have already been mentioned ; and amongthe Orthoptera the great shielded grasshopi^ers are the mostremarkable. The species here figured (Megalodon ensifer) hasthe thorax covered by a large triangular horny shield, two anda half inches long, with serrated edges, a somewhat wavy,hollow surface, and a faint median line, so as very closely toresemble a leaf._The glossy wing-coverts (when fully expanded,more than nine inches across) are of a fine green colour and sobeautifully veined as to imitate closely some of tlie large sinningtropical leaves. Tlie body is short, and terminated ixi thefemale by a long curved sword-like ovij^ositor (not seen in thecut), and the legs are all long and strongly-spined. Theseinsects are sluggish in their motions, depending for safety ontheir resemblance to foliage, their horny shield and wingcoverts,and their spiny legs.The large islands to the east of New Guinea are very little