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LAMARCK, HIS LIFE AND WORK 



would tend to widen the pelvis and to cause the 

 cotyloid cavities to be directed backward ; 



"5. Finally, that a great number of their bones 

 would become fused, and hence several parts of their 

 skeleton would assume an arrangement and a figure 

 conformed to the habits of these animals, and con- 

 trary to what would be necessary for them to have 

 for other habits. 



" Indeed, this can never be denied, because, in fact, 

 nature on a thousand other occasions shows us, in the 

 power exercised by circumstances on habits, and in 

 that of the influence of habits on forms, dispositions, 

 and the proportion of the parts of animals, truly 

 analogous facts. 



" A great number of citations being unnecessary, 

 we now see to what the case under discussion is re- 

 duced. 



" The fact is that divers animals have each, accord- 

 ing to their genus and their species, special habits, 

 and in all cases an organization which is perfectly 

 adapted to these habits. 



" From the consideration of this fact, it appears 

 that we should be free to admit either one or the 

 other of the following conclusions, and that only one 

 of them is susceptible of proof. 



" Conclusion admitted iip to this day : Nature (or its 

 Author), in creating the animals, has foreseen all the 

 possible kinds of circumstances in which they should 

 live, and has given to each species an unchanging 

 organization, as also a form determinate and invariable 

 in its different parts, which compels each species to 

 live in the places and in the climate where we find it, 

 and has there preserved its known habits. 



" My own conclusion : Nature, in producing in suc- 

 cession every species of animal, and beginning with the 

 least perfect or the simplest to end her work with the 

 most perfect, has gradually complicated their struct- 

 ure ; and these animals spreading generally throughout 



