FROM THE GREEKS TO DARWIN 



There is no evidence in this work of the year 

 1802 that Lamarck had seen Darwin's Zoonomia, 

 The parallelism with the Zoonomia comes out 

 much more prominently in Lamarck's most im- 

 portant speculative work, Philosophie Zoolo- 

 gique, published in 1809, in which his earlier 

 views are developed and expanded. This is char- 

 acterized by a clear and beautiful style and by a 

 logical development of the argument, in which 

 Lamarck's whole scheme of Evolution is grad- 

 ually unfolded. His theory was never developed 

 beyond this point, although he restated it in a 

 more condensed form in the introduction to his 

 Histoire Naturelle des Animaua: sans Vertehres 

 between 1815 and 1822. 



The Philosophie Zoologique shows that three 

 truths had now come to him from his labors in 

 botany and zoology, and presumably from his 

 wider readings of earlier writings of Buffon, of 

 Linnseus, and of the Greeks, to whom he makes 

 allusion. These are, first, the certainty that spe- 

 cies vary under changing external influences; 

 second, that there is a fundamental unity in the 

 animal kingdom; third, that there is a progres- 

 sive and perfecting development. Among the di- 

 rect influences of environment he cites the cases 

 of the supposed influence of water upon plants 

 and upon the lower animals ; the influence of air 

 in forming the entire respiratory system of birds ; 



