INSTINCT. 291 



all the disquisitions of human understanding : but 

 our wonder will perhaps cease or diminish, when we 

 consider, that the experimental reasoning itself, which 

 we possess in common with beasts, and on which the 

 whole conduct of life depends, is nothing but a spe- 

 cies of instinct or mechanical power, that acts in us 

 unknown to ourselves ; and in its chief operations is 

 not directed by any such relations or comparisons of 

 ideas as are the proper objects of our intellectual 

 faculties *." 



To prove a similar position, Dr. Darwin traces the 

 experience of animals up to their earliest embryo 

 state. " The chick in the shell," he tells us, " be- 

 gins to move its feet and legs on the sixth day of 

 incubation, or on the seventh day; afterwards it is 

 seen ^to move itself gently in the liquid that sur- 

 rounds it, and to open and shut its mouth. The white 

 of the egg is found in the mouth and gizzard of the 

 chick, and is nearly or quite consumed before it is 

 hatched. The chick, yet in the shell, therefore, has 

 learned to drink by swallowing a part of the white of 

 the egg for its food; but not having experienced 

 how to take up and swallow solid seeds or grains, 

 is either taught by the solicitous industry of its 

 mother, or by repeated attempts is enabled at length 

 to distinguish and to swallow this kind of nourish- 

 ment. 



" It has been deemed," he adds, <c a surprising 

 instance of instinct, that chickens should be able to 

 walk, by a few efforts, almost immediately after their 

 nativity ; whilst the human infant, in those countries 

 where he is not incumbered with clothes, as in India, 

 is live or sixth months, and in our climate almost a 

 twelvemonth, before he can safely stand upon his 

 ieet. The swimming of chickens in the egg resem- 

 bles their manner of walking, which they have thus 

 * Essays, ii. 72, edit, 8vo. Edinb. 1800. 



