ON THE GENETIC VIEW OF NATURE. 339 



the older division of zoology and botany having to a 

 large extent been removed by a study of the inter- 

 dependence of the many forms of living things and 

 their connection with peculiarities of climate and soil. 

 The Darwinian attitude to the study of natural objects 

 has also introduced into the natural sciences the exact 

 spirit of research, accurate measurements, together with 

 elaborate countings, being resorted to in order to decide 

 the range of variability of species, the rate of increase 

 in numbers, and the proportion of the surviving to the 

 lost or wasted specimens. A large amount of statistical 

 information 1 has thus been accumulated, and natural 

 history is becoming to some extent an exact science. 

 That it will ever be so to a very large extent is doubt- 

 ful : it is one of the great merits of Darwin that he has 

 introduced a special method into the sciences of nature 

 the method of a judicious balancing of evidence. He 38. 



The judicial 



was fully ' aware that scarcely a single point was dis- method, 

 cussed in his works on which facts cannot be adduced, 

 often apparently leading to conclusions directly opposite 

 to those at which he arrived, and that a fair result can be 

 obtained only by fully stating and balancing the facts 



natural selection, and must, there- 

 fore, find its explanation in the 

 principle of adaptation or utility " 

 (Wallace. 'Darwinism,' p. 189). 



The term "Mimicry" was first 

 introduced by H. W. Bates in his 

 paper on "Mimetic Butterflies," 

 read before the Liumean Soc. , Nov. 

 18(51, and hailed by Darwin (' Life,' 

 vol. ii. p. 392) as " one of the most 

 remarkable and admirable papers " 

 he ever read. The subject had 

 been passed over in the first editions 

 of the ' Origin,' but was introduced 

 in later editions, and has always 



served as one of the most valuable 

 illustrations and proofs of the 

 theory of natural selection. The 

 whole matter is admirably ex- 

 pounded by Mr Wallace in his 

 long article in the 'Westminster 

 Review,' July 1867, reprinted in 

 his ' Contributions to the Theory 

 of Natural Selection ' (1870, pp. 45- 

 129), and again in 'Darwinism.' 



1 On the development of statis- 

 tical methods in the service of the 

 theory of evolution, see chap. xii. 

 below. 



