Philosophie zoologique ou exposition des considérations relatives à l'histoire naturelle des animaux (meaning "Zoological Philosophy: Exposition with Regard to the Natural History of Animals") is an 1809 book by Jean-Baptiste Lamarck

Jean-Baptiste Lamarck

Jean-Baptiste Pierre Antoine de Monet, Chevalier de la Marck , often known simply as Lamarck, was a French naturalist...

 in which he outlines his theory of evolution now known as Lamarckism

Lamarckism

Lamarckism is the idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring . It is named after the French biologist Jean-Baptiste Lamarck , who incorporated the action of soft inheritance into his evolutionary theories...

.
Lamarck proposed that :

“as new modifications will necessarily continue to
operate, however slowly, not only will there continually be found new
species, new genera, and new orders, but each species will vary in
some part of its structure and form ... individuals which from special
causes are transported into very different situations from those where
the others occur, and then constantly submitted to other influences -
the former, I say, assume new forms, and then they constitute a new
species”

with gaps between differing kinds resulting from the
extinction of intermediate forms

External links

• http://www.ucl.ac.uk/taxome/jim/Mim/lamarck_contents.html
• 1809, vol. I: (Oxford) http://books.google.fr/books?vid=OCLC02210044&hl=en
• 1830, vol. I: (Harvard) http://books.google.fr/books?vid=OCLC11974573&hl=en
• 1830, vol. I: (Michigan) http://books.google.fr/books?vid=OCLC69003856&hl=en
• 1830, vol. II: (Michigan) http://books.google.fr/books?vid=OCLC11974573&hl=en