192 LIFE ON THE EARTH. 



sixteen distinct species. In discussing the geogra- 

 phical distribution of these families of men, and 

 the animals associated with them, M. Charles Des- 

 moulins 1 takes occasion to affirm in the strongest 

 manner the constancy of specific forms, unimpaired 

 by time and physical changes: 



' In future it will be vain to contest the inalter- 

 ability of species, by means of the thousand and one 

 suppositions suggested by ignorance or deception. 

 For example, the carp and the barbel, which differ 

 much less one from the other than a Negro and a 

 Frenchman, have the central parts of their nervous 

 system, different in number, differently arranged and 

 shaped. Evidently cold, heat, light, obscurity, ex- 

 ercise, repose, more or less food, &c. have had no 

 influence on that. 



1 A single objection has been offered to the 

 certainty of these results, and this objection is merely 

 a supposition. It is supposed that the actual diver- 

 sity of species depends on an alteration of primitive 

 forms, either by climate, or by the crossing of allied 

 species, which would thus have multiplied differences, 

 which were afterwards strengthened by time, so that 

 the actual species would be for the most part only 

 accidental varieties rendered definite, one knows not 

 how. 



1 Hist. Nat. des Races Humaines, 1826. 



