804 THE POPULAR SCIENCE MONTHLY. 



shown any advantage derived from this extreme perceptiveness. 

 For making the s and z, the tongue has to be partially applied to 

 a portion of the palate next the teeth. Not only, however, must 

 the contact be incomplete, but its place is indefinite — may be half 

 an inch further back. To make the sh and zli, the contact has to 

 be made, not with the tip, but with the upper surface of the 

 tongue ; and must be an incomplete contact. Though, for making 

 the liquids, the tip of the tongue and the sides of the tongue are 

 used, yet the requisite is not any exact adjustment of the tip, but 

 an imperfect contact with the palate. For the th, the tip is used 

 along with the edges of the tongue ; but no perfect adjustment is 

 required, either to the edges of the teeth, or to the junction of the 

 teeth with the palate, where the sound may equally well be made. 

 Though for the t and d complete contact of the tip and edges of 

 the tongue with the palate is required, yet the place of contact is 

 not definite, and the tip takes no more important share in the 

 action than the sides. Any one who observes the movements of 

 his tongue in speaking, will find that there occur no cases in 

 which the adjustments must have an exactness corresponding to 

 the extreme power of discrimination which the tip possesses : for 

 speech, this endowment is useless. Even were it useful, it could 

 not be shown that it has been developed by survival of the fittest ; 

 for though perfect articulation is useful, yet imperfect articula- 

 tion has rarely such an effect as to impede a man in the mainte- 

 nance of his life. If he is a good workman, a German's inter- 

 changes of b's and p's do not disadvantage him. A Frenchman 

 who, in place of the sound of th, always makes the sound of z, 

 succeeds as a teacher of music or dancing, no less than if he 

 achieved the English pronunciation. Nay, even such an imper- 

 fection of speech as that which arises from cleft palate, does not 

 prevent a man from getting on if he is capable. True, it may go 

 against him as a candidate for Parliament, or as an " orator " of 

 the unemployed (mostly not worth employing). But in the 

 struggle for life he is not hindered by the effect to the extent of 

 being less able than others to maintain himself and his offspring. 

 Clearly, then, even if this unparalleled perceptiveness of the 

 tongue-tip is required for perfect speech, this use is not suffi- 

 ciently important to have been developed by natural selection. 



How, then, is this remarkable trait of the tongue-tip to be ac- 

 counted for ? Without difficulty, if there is inheritance of ac- 

 quired characters. For the tongue-tip has, above all other parts 

 of the body, unceasing experiences of small irregularities of sur- 

 face. It is in contact with the teeth, and either consciously or 

 unconsciously is continually exploring them. There is hardly a 

 moment in which impressions of adjacent but different positions 

 are not being yielded to it by either the surfaces of the teeth or 





