238 EVOLUTION, OLD AND NEW. 



" The ' Encydopedie methodiqtie,' begun by Diderot 

 and D'Alembert, was not yet completed. For this work 

 Lamarck wrote four volumes, describing all the then 

 known plants whose names began with the letters from 

 A to P. This great work was completed by Poiret, 

 and comprises twelve volumes, which appeared between 

 the years 1783 and 1817. A still more important work, 

 also part of the Encyclopedia, and continually quoted 

 by botanists, is the ' Illustration des Genres.' In this 

 work Lamarck describes two thousand genera, and 

 illustrates them, according to the title-page, with nine 

 hundred engravings. Only a botanist can form any idea 

 of the research in collections, gardens, and books, which 

 such a work must have involved. But Lamarck's activity 

 was inexhaustible. Sonnerat returned from India in 

 1781 with a very large number of dried plants ; no one 

 except Lamarck thought it worth while to inspect them, 

 and Sonnerat, charmed with his enthusiasm, gave him 

 the whole magnificent collection. 



"In spite, however, of his incessant toil, Lamarck's 

 position continued to be most precarious. He lived by 

 his pen, as a publisher's hack, and it was with difficulty 

 that he obtained even the poorly paid post of keeper of 

 the king's cabinet of dried plants. Like most other 

 naturalists he had thus to contend with incessant diffi- 

 culties during a period of fifteen years. 



"At length fortune bettered his condition while 

 changing the direction of his labours. • France was now 

 under the Convention ; what Carnot had done for the 

 army Lakanal undertook to do for the natural sciences. 

 At his suggestion a museum of natural history was 



