PDF - Wallace Online

452 TROPICAL NATUREanatomy could be appliedto the classification of animalsaccording to their whole organisationin a far more naturalmanner than by the easier method of Linnaeus. Later on,when improved microscopes and refined optical and chemicaltests became available, the study of anatomy was carriedbeyond the knowledge of the parts and organs of the bodysuch as bones, muscles, blood-vessels, and nerves to theinvestigation of the tissues, fibres, and cells of which theseare composed while the; physiologists devoted themselves toan inquiry into the mode of action of this complex machinery,so as to discover the use of every part, the nature of itsfunctions in health and disease, and, as far as possible, thenature of the forces which kept them all in action.Down to the middle of the present century the study ofnature advanced with giant strides along these separate linesof research, while the vastness and complexity of the subjectled to a constantly increasing specialisation and division oflabour among naturalists, the result being that each group ofinquirers came to look upon his own department as more orless independent of all the others, each seemed to think thatany addition to his body of facts was an end in itself, and thatany bearing these facts might have on other branches of thestudy or on the various speculations as to the "system ofnature " or the " true method of classification " that had atvarious times been put forth was an altogether subordinateand unimportant matter. And, in fact, they could hardlythink otherwise. For, while there was much talk of the"unity of nature," a dogma pervaded the whole scientificworld which rendered hopeless any attempt to discover thissupposed unity amid the endless diversity of organic formsand structures, while so much of it as might be detectedwould necessarily be speculative and unfruitful. This dogmawas that of the original diversity and permanent stability ofspecies, a dogma which the rising generation of naturalistsmust find it hard to believe was actually held, almostuniversally, by the great men they look up to as masters intheir several departments, and held for the most part withan unreasoning tenacity and scornful arrogance more suitedto politicians or theologians than to men of science. Althoughthe doctrine of the special and independent creation of every