23 



higher forms of life from lower forms, has, as is well known, 

 been considered for a great many centuries. In the Greek 

 period, in the fifth century, B.C., Anaxagoras and Democritus 

 introduced what, in a developed and somewhat modified 

 form, is to-day known as Adaptation. Anaxagoras de- 

 clared that "animals would have been men had they had 

 hands". Empedocles held that all things found themselves 

 together, and those which were suited to each other remained 

 together. This is already a forecast of the idea of 'survival of 

 the fittest'. Aristotle gives us the first distinct idea of a 

 struggle from lower to higher forms. " It is due to the resist- 

 ance of matter to form, " he states, "that nature can only rise 

 by degrees from lower to higher types." In mediaeval times 

 one of the greatest of the many who spoke in favour of the 

 theory of descent was Augustine, in the fifth century. But 

 such speculations were placed in an entirely new light when 

 Harvey, in 1619, discovered the function of the heart in the 

 circulation of the blood. Buffon (1707-1788) laid in Zoology 

 and Botany the basis of modern biological evolution. Accord- 

 ing to his view, classification was the invention of man, and 

 species were mutable in relation to change of environment. 

 Bonnet, a few years later, was the author of the term 

 'evolution'. 



2. ERASMUS DARWIN. 



In Erasmus Darwin 1 we find a theory of the origin of life 

 from 'filaments' analogous to what we to-day call 'protoplas- 

 mic masses'. His general theory of descent is that "all 

 animals undergo transformations which are in part produced 

 by their own exertions in response to pleasures and pains, and 

 many of these acquired forms or propensities are transmitted 

 to their posterity". Here we notice the introduction of pleas- 

 ure and pain into biology to account for certain modifications. 

 This application would not be remarkable had Erasmus 

 Darwin lived after Bain, but, coming when it did, it suggests 

 the necessity of utilizing the psychical as an explanation of 

 the process of evolution quite as much as the facts of physi- 

 ology are needed in the explanation of psychical phenomena, 

 the ultimate relation of the two, in other words, being not yet 

 settled. 



3. LAMARCK, CHAMBERS. 



Finally, in Lamarck, 1809, we have the inventor of the 

 modern theory of descent. "Animals were evolved, not by 

 the direct external action of environment, but by environment 



1 "Zoonomia, or The Laws of Organic Life", 1794-96. 



