274 RECENT PROGRESS OF THE THEORY OF VISION. 



often turns obstinately away from it to the wrong side and tries 

 to find it there. The young chicken very soon pecks at grains 

 of corn, but it pecked while it was still in the shell, and when 

 it hears the hen peck, it pecks again, at first seemingly at 

 random. Then, when it has by chance hit upon a grain, it 

 may, no doubt, learn to notice the field of vision which is at the 

 moment presented to it. The process is all the quicker because 

 the whole of the mental furniture which it requires for its life 

 is but small. 



We need, however, further investigations on the subject in 

 order to throw light upon this question. As far as the observa- 

 tions with which I am acquainted go, they do not seem to me to 

 prove that anything more than certain tendencies is born with 

 animals. At all events one distinction between them and man 

 lies precisely in this, that these innate or congenital tendencies, 

 impulses or instincts are in him reduced to the smallest possible 

 number and strength. 1 



There is a most striking analogy between the entire range 

 of processes which we have been discussing, and another System 

 of Signs, which is not given by nature, but arbitrarily chosen, 

 and which must undoubtedly be learned before it is understood. 

 I mean the words of our mother tongue. 



Learning how to speak is obviously a much more difficult 

 task than acquiring a foreign language in after life. First, the 

 child has to guess that the sounds it hears are intended to be 

 signs at all ; next, the meaning of each separate sound must be 

 foxind out, by the same kind of induction as the meaning of 

 the sensations of sight or touch ; and yet we see children by the 

 end of their first year already understanding certain words and 

 phrases, even if they are not yet able to repeat them. We may 

 sometimes observe the same in dogs. 



Now this connection between Names and Objects, which 

 demonstrably must be learnt, becomes just as firm and inde- 

 structible as that between Sensations and the Objects which 

 produce them. We cannot help thinking of the usual sigriifica- 



1 See on this subject Bain on the Senes and the Intellect, p. 293 ; also a 

 paper on ' Instinct ' in Nature, Oct. 10, 1872. 



