FIFTH DAY. | INSTINCTS. 137 



by associations, so that a child must learn to walk as 

 he learns to swim or write ; * but in the colt or chicken, 

 the limbs are formed with the powers of motion; 

 and these animals walk as soon as they have quitted 

 the womb or the egg. 



PHYS. I believe it possible that they may have 

 acquired these powers of motion in the embryo state ; 

 and I think I have observed, that birds learn to fly, 

 and acquire the use of their wings, by continued 

 efforts, in the same manner as a child does that of 

 his limbs. 



ORN. I cannot agree with you; the legs of the 

 fetus are folded up in the womb of the mare ; and 

 neither the colt nor the chicken can ever have per- 

 formed, in the embryo state, any motions of their legs 

 similar to those which they have perfectly at their 

 command when born. Young birds cannot fly as 

 soon as they are hatched, because they have no wing 

 feathers ; but as soon as these are developed, and 

 even before they are perfectly strong, they use their 

 wings, fly, and quit their nests without any education 

 from their parents. Compare a young quail, when a 



* [But it cries and sucks, and each with as perfect effect, at the 

 instant of birth, as days or weeks after, its organs at the time of 

 birth, being sufficiently developed for these its needs, one to excite 

 the mother's regards, the other to support life. Both acts may perhaps 

 be considered instinctive, being complete without teaching or thought ; 

 and so in accordance with the reasoning in the text. J.D.] 



