Influence of circumstances on the Actions of Animals. 969 
should have created for the parts of the animal as many forms as 
the diversity of the circumstances in which they had to live would 
have required, and that these forms as these circumstances should 
never have varied. This is certainly not the order of things which 
exists, and if it were really such we would not have the race-horses 
of the form of those in England. We would not have great 
draught-horses, so heavy and so different from the former. For 
had not nature herself produced the like, we would not have, for 
the same reason, lapdogs with slender limbs, greyhounds so agile 
in running, water-dogs, ete. We would not have poultry without 
tails, peacocks, pigeons, etc.; finally we would not be able to culti- 
vate wild plants, as we please, in the rich and fertile soil of our 
gardens, without fearing to see them change by long culture. For 
along time there has been in this respect a sentiment which has 
established the following saying, which has passed into a proverb, 
which all the world knows, that “habits form a second nature.” 
Surely if the habits and the nature of each animal never varied, 
the proverb would have been false, and would not have been used 
for the cases to which it had been applied. 
If people considered seriously all that I have just shown, they 
would know that I was well grounded in reasons when, in my 
work entitled “Recherches sur les corps vivans,” p. 50, I estab- 
lished the following proposition: “It is not the organ, that is to 
say, the nature and form of the parts of the body of an animal 
which have given origin to its habits and peculiar functions, but it 
is, on the contrary, its habits, its manner of life and the circum- 
stances in which individuals from which it came, found themselves, 
which have after a time constituted the form of its body, the num- 
ber and character of its organs, and finally the functions which it 
possesses. Let us weigh well this proposition, and give to it all the 
attention which nature and the condition of things continually gives 
us opportunity, Then its importance and its truth will become 
perfectly clear. 
Time and favorable circumstances being, as I have already said, 
the two principal means which nature employs in giving existence 
to all her productions, it is evident that time has no limit for her, 
and in consequence she has it always at her disposal. Concerning 
these circumstances, which she requires, and which she still uses 
