Previous directors of the museum included many of the scientists he discusses in this book: George Cuvier (1822–1823, 1826–1827, 1830–1831), Isidore Geoffrey St Hilaire (1860– 1861), and Alphonse Milne-Edwards (1891–1900).

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations.

A.L.S. (1912 Oct. 12, Paris) on teaching geology ; on letterhead of the Museum d'Histoire Naturelle ; in French.