26 GENERAL PRINCIPLES OF ZOOLOGY. 



Darwin's Predecessors. Already in Cuvier's time 

 there prevailed a strong current in favor of this theory. It 

 found expression in England in the writings of Erasmus- 

 Darwin (grandfather of the renowned Charles Darwin) ; in 

 Germany in the works of Goethe, Oken, and the disciples 

 of their school of natural philosophy; in France the 

 genealogical theory was built up particularly by Buffon, 

 Geoffrey St. Hilaire, and Lamarck. Its completest ex- 

 pression was found in Lamarck's " Philosophic zoolo- 

 gique " which appeared in 1809; its arguments will be con- 

 sidered in the following paragraphs. 



Lamarck (Jean Baptiste de Monet, Chevalier de La- 

 marck, born in Picardy, 1744, died, Professor at the 

 Jardin des Plantes, 1829) taught that on the earth at first 

 organisms of the simplest structure arose in the natural 

 way through spontaneous generation from non-living 

 matter. From these simplest living creatures have de- 

 veloped in the course of an immeasurably vast space of 

 time, by gradual changes, the at present living species of 

 plants and animals, without any break in the continuity of 

 life upon our globe ; the terminal point of this series is 

 man ; the other animals are the descendants of those forms 

 from which man has developed. Lamarck, in agreement 

 with the then prevailing conceptions, regarded the animal 

 kingdom as a series grading from the lowest primitive 

 animal up to man. Among the causes which may influ- 

 ence the change and perfecting of organisms, Lamarck 

 emphasized particularly use and disuse; the giraffe has 

 obtained a long neck because by a special condition of 

 life he was compelled to stretch, in order to browse the 

 leaves on high trees ; conversely, the eyes of animals which 

 live in the dark have from lack of use degenerated into> 

 small functionless bodies. The direct influence of the ex- 

 ternal world must be unimportant ; the changes in the 

 surroundings (Geoffrey St. Hilaire's Ic vwnde ambient] 

 must for the most part act indirectly upon animals by 

 altering the conditions for the use of organs. 



