PDF - Wallace Online

IllMIMICRY,AND OTHER PROTECTIVE RESEMBLANCES AMONGANIMALSTHERE is no more convincing proof of the truth of a comprehensivetheory than its power of absorbing and findinga place for new facts, and its capability of interpretingphenomena which had been previously looked upon as unaccountableanomalies. It is thus that the law of universalgravitation and the undulatory theory of light have becomeestablished and universally accepted by men of science.Fact after fact has been brought forward as being apparentlyinconsistent with them, and one after another these veryfacts have been shown to be the consequences of the lawsthey were at first supposed to disprove. A false theory willnever stand this test.Advancing knowledge brings to lightwhole groups of facts which it cannot deal with, and itsadvocates steadily decrease in numbers, notwithstanding theability and scientific skill with which it may have beensupported. The great name of Edward Forbes did notprevent his theory of " Polarity in the distribution of Organicbeings in Time " from dying a natural death ;but the moststriking illustration of the behaviour of a false theory is tobe found in the " "Circular and Quinarian System of classificationpropounded by MacLeay, and developed by Swainson,with an amount of knowledge and ingenuity that hasrarely been surpassed. This theory was eminently attractive,both from itssymmetry and completeness, and fromthe interesting nature of the varied analogies and affinities1 First published in the Westminster Review, July 1867 ; reprinted in1870 with additions and corrections.