1 84 LAMARCK, HIS LIFE AND WORK 



ness, and better satisfies the views now prevailing, 

 than that of any other author. 



His definition of a species is as follows : 



" Every collection of similar individuals, perpetu- 

 ated by generation in the same condition, so long 

 as the circumstances of their situation do not change 

 enough to produce variations in their habits, charac- 

 ter, and form." 



Lamarck's rare skill, thoroughness, and acuteness 

 as an observer, combined with great breadth of view, 

 were also supplemented by the advantages arising 

 from residence in Paris, and his connection with 

 the Museum of Natural History. Paris was in the 

 opening years of the nineteenth century the chief 

 centre of biological science. France having con- 

 valesced from the intestinal disorders of the Revolu- 

 tion, and, as the result of her foreign wars, adding to 

 her territory and power, had begun with the strength 

 of a young giant to send out those splendid exploring 

 expeditions which gathered in collections in natural 

 history from all parts of the known or accessible 

 world, and poured them, as it were, into the laps of 

 the professors of the Jardin des Plantes. The shelves 

 and cases of the galleries fairly groaned with the 

 weight of the zoological riches which crowded them. 

 From the year 1800 to 1832 the French government 

 showed the greatest activity in sending out explor- 

 ing expeditions to Egypt, Africa, and the tropics.* 



* During the same period (1803-1829) Russia sent out expeditions 

 to the North and Northeast, accompanied by the zoSlogists Tilesius, 

 Langsdorff, Chamisso, Eschscholtz, and Brandt, all of them of Ger- 



