420 THE STUDY OF ANIMAL LIFE CHAP. 



the characteristic Lamarckian theory of the transforming 

 power of use and disuse :- 



" Every considerable and sustained change in the surroundings 

 of any animal involves a real change in its needs." 



" Such change of needs involves the necessity of changed action 

 in order to satisfy these needs, and, in consequence, of new habits." 



" It follows that such and such parts, formerly less used, are 

 now more frequently employed, and in consequence become more 

 highly developed ; new parts also become insensibly evolved in the 

 creature by its own efforts from within.' 



/ 



' These gains or losses of organic development, due to use or 

 disuse, are transmitted to offspring, provided they have been 

 common to both sexes, or to the animals from which the offspring 

 have descended." 



The historian of evolution theories has, of course, to 

 take account of many workers besides Buffon, Erasmus 

 Darwin, and Lamarck ; of Treviranus (1776-1837), whose 

 Biology or Philosophy of Living Nature (1802-1805) is 

 full of evolutionary suggestions ; of Geoffroy St. Hilaire, 

 who in 1830, before the French Academy of Science, 

 fought with Cuvier, the fellow-worker of his youth, an 

 intellectual duel on the question of descent ; of Goethe, 

 who, in his eighty-first year, heard the tidings of Geof- 

 froy's defeat with an interest which transcended the 

 political anxieties of the time, and whose own epic of 

 evolution surpasses that of Lucretius ; of Oken's specu- 

 lative mist, amid which the light of evolutionary ideas 

 danced like a will-o'-the-wisp ; of many others in whose 

 mind the truth grew if it did not blossom. But we must 

 now pass to the \vork of Charles Darwin. 



6. Darwin. Marcus Aurelius gave thanks in his roll of 

 blessings that he had not been suffered to keep quails ; so 

 Darwin, in recounting his mercies, did not forget to be 

 grateful for having been preserved from the snare of 

 becoming a specialist. From a more partial point of 

 view, we have reason to be thankful that he became a 

 specialist, not in one department, but in many. As a 

 disciple of Linnaeus, he described the species of barnacles 

 in one volume, and followed in the steps of Cuvier in 

 anatomising them in another. Of tissues and cells he 

 knew less, being as regards these items an antediluvian, 



