246 LAMARCK, ms LIFE AND WORIC 



kind. Finally, this change propagates itself and is 

 then handed down {se passe) to all the individuals which 

 succeed and which are submitted to the same circum- 

 stances, without their having been obliged to acquire 

 it by the means which have really created it. 



" Besides, in the unions between the sexes the in- 

 termixtures between individuals which have different 

 qualities or forms are necessarily opposed to the con- 

 stant propagation of these qualities and forms. We 

 see that which in man, who is exposed to such different 

 circumstances which influence individuals, prevents 

 the qualities of accidental defects which they have 

 happened to acquire from being preserved and propa- 

 gated by heredity {g^n&ation). 



" You can now understand how, by such means and 

 an inexhaustible diversity of circumstances, nature, 

 with sufficient lengj^fcof time, has been able to and 

 should produce all^rcse results. 



" If I should choose here to pass in review all the 

 classes, orders, genera, and species of animals in exist- 

 ence I could make you see that the structure of in- 

 dividuals and their organs, faculties, etc., is solely the 

 result of circumstances to which each species and 

 all its races have been subjected by nature, and of 

 habits that the individuals of this species have been 

 obliged to contract. 



" The influences of localities and of temperatures 

 are so striking that naturalists have not hesitated to 

 recognize the effects on the structure, the develop- 

 ments, and the faculties of the living bodies subject to 

 them. 



" We have long known that the animals inhabiting 

 the torrid zone are very different from those which 

 live in the other zones. Buffon has remarked that 

 even in latitudes almost the same the animals of the 

 new continent are not the same as those of the old. 



" Finally the Count Lac^pfede, wishing to give to 

 this well-founded fact the precision which he believed 



