168 PHILOSOPHY OF ZOOLOGY. 



must be confined to the feet and head. We accordingly 

 find, that the villous surface of the skin is very conspicu- 

 ous in the soles of the feet, particularly of rapacious birds, 

 which use their toes for seizing their prey. In those birds 

 with long bills, as snipes and woodcocks, which search for 

 food among mud, the extremities of the mandibles are usu- 

 ally of a softer texture than the base, and evidently appear 

 to possess an exquisite degree of sensibility. 



But, even in those animals whose skin is considered as 

 destitute of a villous surface, the presence of the sense of 

 touch may be distinctly ascertained. In Fishes, the surface 

 is covered with insensible scales; yet the contact of an ob- 

 ject with the body is readily felt. About the mouth and 

 head, however, of many species, there are places destitute of 

 scales, usually more or less raised above the surface, which 

 are usually considered as subservient to the purposes of 

 touch, although the evidence of their utility in this respect 

 is far from satisfactory. These are soft in their texture,,, 

 pliable, and capable of various motions. They obtain diffe- 

 rent names, according to their situation. When placed upon 

 the lips, they are termed cirr/ii, on the head tentacula, and 

 on other parts of the body fingers. In the Mollusca, the 

 sense of touch more particularly resides in the tentacula. We 

 may observe the application of these organs to the examina- 

 tion of the surface of bodies in the common slug. Among 

 Insects, the antennae, or feelers, as they are termed, are or- 

 gans of touch, possessing, in some species, very great sen- 

 sibility. Even among the Zoophytes, the sense of touch is 

 present. By means of the cirrhi which surround their 

 mouth, they are warned of the presence of their prey. 



In the examination of the appearance of the sense of touch 

 in the imperfect animals, it is difficult to ascertain, whether, 

 the information obtained by these cirrhi is confined to sen- 



