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ound in Ceram； which is only sixty miles from Mysol。 Another small marsupial animal （Perameles doreyanus） is common to Aru and New Guinea。 The insects show exactly the same results。 The butterflies of Aru are all either New Guinea species； or very slightly modified forms； whereas those of Ceram are more distinct than are the birds of the two countries。
It is now generally admitted that we may safely reason on such facts as those； which supply a link in the defective geological record。 The upward and downward movements which any country has undergone； and the succession of such movements； can be determined with much accuracy； but geology alone can tell us nothing of lands which have entirely disappeared beneath the ocean。 Here physical geography and the distribution of animals and plants are of the greatest service。 By ascertaining the depth of the seas separating one country from another； we can form some judgment of the changes which are taking place。 If there are other evidences of subsidence； a shallow sea implies a former connexion of the adjacent lands； but i￡ this evidence is wanting； or if there is reason to suspect a rising of the land； then the shallow sea may be the result of that rising； and may indicate that the two countries will be joined at some future time； but not that they have previously been so。 The nature of the animals and plants inhabiting these countries will； however； almost always enable us to determine this question。 Mr。 Darwin has shown us how we may determine in almost every case； whether an island has ever been connected with a continent or larger land； by the presence or absence of terrestrial Mammalia and reptiles。 What he terms 〃oceanic islands 〃possess neither of these groups of animals； though they may have a luxuriant vegetation； and a fair number of birds； insects； and landshells； and we therefore conclude that they have originated in mid…ocean； and have never been connected with the nearest masses of land。 St。 Helena； Madeira； and New Zealand are examples of oceanic islands。 They possess all other classes of life； because these have means of dispersion over wide spaces of sea； which terrestrial mammals and birds have not； as is fully explained in Sir Charles Lyell's 〃Principles of Geology；〃 and Mr。 Darwin's 〃Origin of Species。〃 On the other hand； an island may never have been actually connected with the adjacent continents or islands； and yet may possess representatives of all classes of animals； because many terrestrial mammals and some reptiles have the means of passing over short distances of sea。 But in these cases the number of species that have thus migrated will be very small； and there will be great deficiencies even in birds and flying insects； which we should imagine could easily cross over。 The island of Timor （as I have already shown in Chapter XIII） bears this relation to Australia； for while it contains several birds and insects of Australian forms； no Australian mammal or reptile is found in it； and a great number of the most abundant and characteristic forms of Australian birds and insects are entirely absent。 Contrast this with the British Islands； in； which a large proportion of the plants； insects； reptiles； and Mammalia of the adjacent parts of the continent are fully represented； while there are no remarkable deficiencies of extensive groups； such as always occur when there is reason to believe there has been no such connexion。 The case of Sumatra； Borneo； and Java； and the Asiatic continent is equally clear； many large Mammalia； terrestrial birds； and reptiles being common to all； while a large number more are of closely allied forms。 Now； geology has taught us that this representation by allied forms in the same locality implies lapse of time； and we therefore infer that in Great Britain； where almost every species is absolutely identical with those on the Continent； the separation has been very recent； while in Sumatra and Java； where a considerable number of the continental species are represented by allied forms； the separation was more remote。
From these examples we may see how important a supplement to geological evidence is the study of the geographical distribution of animals and plants； in determining the former condition of the earth's surface； and how impossible it is to understand the former without taking the latter into account。 The productions of the Aru Islands offer the strangest evidence； that at no very distant epoch they formed a part of New Guinea； and the peculiar physical features which I have described； indicate that they must have stood at very nearly the same level then as they do now； having been separated by the subsidence of the great plain which formerly connected them with it。
Persons who have formed the usual ideas of the vegetation of the tropics who picture to themselves the abundance and brilliancy of the flowers； and the magnificent appearance of hundreds of forest trees covered with masses of coloured blossoms； will be surprised to hear； that though vegetation in Aru is highly luxuriant and varied； and would afford abundance of fine and curious plants to adorn our hothouses； yet bright and showy flowers are； as a general rule； altogether absent； or so very scarce as to produce no effect whatever on the general scenery。 To give particulars： I have visited five distinct localities in the islands； I have wandered daily in the forests； and have passed along upwards of a hundred miles of coast and river during a period of six months； much of it very fine weather； and till just as I was about to leave； I never saw a single plant of striking brilliancy or beauty； hardly a shrub equal to a hawthorn； or a climber equal to a honeysuckle！ It cannot be said that the flowering season had not arrived； for I saw many herbs； shrubs； and forest trees in flower； but all had blossoms of a green or greenish…white tint； not superior to our lime…trees。 Here and there on the river banks and coasts are a few Convolvulaceae； not equal to our garden Ipomaeas； and in the deepest shades of the forest some fine scarlet and purple Zingiberaceae； but so few and scattered as to be nothing amid the mass of green and flowerless vegetation。 Yet the noble Cycadaceae and screw…pines； thirty or forty feet high； the elegant tree ferns； the lofty palms； and the variety of beautiful and curious plants which everywhere meet the eye； attest the warmth and moisture of the tropics； and the fertility of the soil。
It is true that Aru seemed to me exceptionally poor in flowers； but this is only an exaggeration of a general tropical feature； for my whole experience in the equatorial regions of the west and the east has convinced me； that in the most luxuriant parts of the tropics； flowers are less abundant； on the average less showy； and are far less effective in adding colour to the landscape than in temperate climates。 I have never seen in the tropics such brilliant masses of colour as even England can show in her furze…clad commons； her heathery mountain…sides； her glades of wild hyacinths； her fields of poppies； her meadows of buttercups and orchisescarpets of yellow； purple； azure…blue； and fiery crimson； which the tropics can rarely exhibit。 We； have smaller masses of colour in our hawthorn and crab trees； our holly and mountain…ash； our boom； foxgloves； primroses； and purple vetches； which clothe with gay colours the whole length and breadth of our land； These beauties are all common。 They are characteristic of the country and the climate； they have not to be sought for； but they gladden the eye at every step。 In the regions of the equator； on the other hand； whether it be forest or savannah； a sombre green clothes universal nature。 You may journey for hours； and even for days； and meet with nothing to break the monotony。 Flowers are everywhere rare； and anything at all striking is only to be met with at very distant intervals。
The idea that nature exhibits gay colours in the tropics； and that the general aspect of nature is there more bright and varied in hue than with us； has even been made the foundation of theories of art； and we have been forbidden to use bright colours in our garments； and in the decorations of our dwellings； because it was supposed that we