THEORIES OF ORGANIC EVOLUTION 



tion of a line of organisms where does the possibility 

 of modification of organic type find its bounds ? Why 

 may not the modification of parts go on along devious 

 lines until the remote descendants of an organism are 

 utterly unlike that organism ? Why may we not thus 

 account for the development of various species of be- 

 ings all sprung from one parent stock ? That, too, is a 

 poet's dream ; but is it only a dream ? Goethe thought 

 not. Out of his studies of metamorphosis of parts 

 there grew in his mind the belief that the multitudinous 

 species of plants and animals about us have been 

 evolved from fewer and fewer earlier parent types, like 

 twigs of a giant tree drawing their nurture from the 

 same primal root. It was a bold and revolutionary 

 thought, and the world regarded it as but the vagary of 

 a poet. 



ERASMUS DARWIN 



Just at the time when this thought was taking form 

 in Goethe's brain, the same idea was germinating in 

 the mind of another philosopher, an Englishman of in- 

 ternational fame, Dr. Erasmus Darwin, who, while he 

 lived, enjoyed the widest popularity as a poet, the 

 rhymed couplets of his Botanic Garden being quoted 

 everywhere with admiration. And posterity repudi- 

 ating the verse which makes the body of the book, yet 

 grants permanent value to the book itself, because, 

 forsooth, its copious explanatory foot-notes furnish an 

 outline of the status of almost every department of 

 science of the time. 



But even though he lacked the highest art of the 

 versifier, Darwin had, beyond perad venture, the imagi- 

 nation of a poet coupled with profound scientific knowl- 



