PDF - Wallace Online

456 TROPICAL NATUREof comparing the productions of one country with those ofanother of ; investigating the physical and biological relationsof islands and continents; of watching the struggle forexistence in regions where civilisation has not disturbed thefree action and reaction of the various groups of animals andplants on each other ; and, what is perhaps more importantstill, the ample leisure to ponder again and again on everyphase of the phenomena which presented themselves, freefrom the attractions of society and the disturbing excitementof daily association with contemporary men of science,these are the conditions most favourable to the formation ofhabits of original thought, and the months and years whichat first sight appear intellectually wasted in the companionshipof uncivilised man, or in the solitary contemplation ofnature, are those in which the seed was sown which wasdestined to produce in after years the mature fruit of greatphilosophical conceptions. Let us then first glance over theJournal of Researches, in which are recorded the main factsand observations which struck the young traveller, and seehow far we can detect here the germs of those ideas andproblems to the working out of which he devoted a long andlaborious life.The Journal of ResearchesThe question of the causes which have produced the distributionand the dispersal of organisms seems to have beena constant subject of observation and meditation. At anearly period of the voyage he collected infusorial dust whichfell on the ship when at sea, and he notes the suggestive factthat in similar dust collected on a vessel 300 miles from landhe found particles of stone above the thousandth of an inchsquare, and remarks": After this fact, one need not be surprisedat the diffusion of the far lighter and smaller sporulesof cryptogamic plants." He records many cases of insectsoccurring far out at sea, on one occasion when the nearestland was 370 miles distant. He paid special attention to theinsects and plants inhabiting the Keeling or Cocos, and otherrecently formed coralline or volcanic islands ;the contrast ofthese with the peculiar productions of the Galapagos evidentlyimpressed him profoundly ;while the remarkable facts pre-