324 PRACTICAL AND SCIENTIFIC ZOOLOGY. 



rally used the term normal in the same sense as we 

 apply the word typical; but we have preferred the 

 latter, throughout the whole of this work, as being more 

 expressive. 



(393.) We shall now attempt another mode of ex- 

 plaining the difference between typical and aberrant 

 groups, which will bring the matter home to the most 

 ordinary capacity. Let the reader suppose that each of 

 his five fingers represents one of the five divisions of 

 every circle. Let him further suppose the thumb and 

 forefinger to represent the two typical groups, and the 

 three others, the aberrant. The first, or typical groups, 

 as before stated, are always the most perfect ; that is, 

 they are distinguished by possessing more strength, 

 and are endowed with greater qualifications or perfec- 

 tions, than any others. Now, the thumb and the fore- 

 finger are the most important to the human hand : 

 consider for a moment the strength and security which 

 is given by the thumb to every office which the hand 

 performs : how weak would be our grasp, how unsteady 

 our writing, how insecure our handling, if we were un- 

 fortunately deprived of this member ! The loss of any 

 one, or even of any two, of our three last fingers would 

 not subject us to half the inconvenience of the loss of the 

 thumb. The forefinger is nearly as important : it acts 

 more immediately in unison with the thumb, and is only 

 inferior to it in strength and utility. It matters not 

 whether this prevalent use of the forefinger is the result 

 of habit ; nor is it any argument against the assertion 

 to urge, that a man who loses his forefinger, or even 

 his thumb, may, nevertheless, acquire the power of 

 doing almost every thing necessary with his remaining 

 fingers. The first two were manifestly intended to be 

 more used than the others ; and a greater power, or, 

 what is the same thing, a greater perfection, has conse- 

 quently been given to them. So far, then, for an illus- 

 tration of the two typical groups. The aberrant groups 

 are three : they always preserve a sufficient similarity 

 to the two others to show their absolute connection 



