28 COMPARISONS OF STRUCTURE IN ANIMALS. 



hammer with a strenuous grip ; it guides the 

 pencil and the pen, or runs over the ivory- 

 keys of the piano with astonishing rapidity 

 and precision. It accommodates its move- 

 ments, its pressure, its force, its manipulation, 

 to every exigency ; it spins the thread from 

 the distaff, and tests the deUcacy of fabrics. 

 It is not only an organ of prehension, it is the 

 great organ of touch or tact ; it ascertains the 

 texture, the form, the smoothness, or hardness, 

 the resistance, or compressibility of bodies 

 subjected to its action ; it, in fact, assists the 

 eye in the task of ascertaining the qualities, 

 and even the nearness or distance of objects 

 presented to our senses. Nor is this all — it 

 aids us in the expression of om- feelings and 

 passions. By the movements of the hands we 

 invite, we repel, we command, we implore, we 

 rejoice, we pardon, and even note the regularly 

 recurring intervals of time ; as in musical per- 

 foi'mances. 



We shall not enter into the anatomical 

 details of the hand, and to describe the form 

 seems superfluous. We know that the four 

 fingers, composed each of three joints, are of 

 unequal length and strength, and are capable 

 of being folded down more or less independ- 



