

280 I'HiMKsoiTiv OF ZOOLOGY. 



the conditions requisite for receiving this kind of education. 

 It is obvious, that there is required a peculiar organization, 

 in order, not merely to utter the natural sounds, but to modify 

 in tone, intensity, and expression, the sounds which can be 

 produced, so as to resemble the notes which are to be acqui- 

 red. This capability of the organs to modify themselves to 

 acquire particular sounds to any extent, only lasts during the 

 period of youth. Afterwards, the muscles of the voice are not 

 so obedient to the will, and it becomes difficult to learn to 

 pronounce readily, sounds to which we have not been previ- 

 ously accustomed. To this cause may be referred the extreme 

 difficulty of ceasing to use the accent of one^s native tongue, 

 and of acquiring that of a foreign language. There is, how- 

 ever, a second condition, on which this susceptibility of ac- 

 quiring language greatly depends, namely, quickness of 

 hearing. In order to learn to imitate sounds, it is neces- 

 sary that we be able to discriminate their qualities accu- 

 rately, to know what we are to imitate, and determine on 

 our degree of success. A delicate ear, therefore, is essen- 

 tially requisite, and as it chiefly exists in early life, when 

 the organ of hearing is in the soundest state, we may dis- 

 cover one reason, at least, why the young learn to pro- 

 nounce new sounds more readily than the old. But, even 

 with the existence of organs capable of articulating an ac- 

 quired language, and a delicate ear to discriminate sounds, 

 there is required the desire of imitation to induce us to ex- 

 ert these organs in producing a resemblance to the sounds 

 we hear. It often happens, particularly among birds, that 

 the power of imitation is scarcely exerted in any other 

 manner. 



By attending to the conditions requisite to acquire lan- 

 guage, we perceive the reason why persons born deaf are 

 at the same time dumb. They do utter, indeed, the sounds 

 of natural language, expressive of their feelings, but as 



