TOUCH. 195 



make with their points so many parts of the periphery 

 of a circle, of an extent at least equal to the circum- 

 ference of any part of their own bodies. With this 

 instrument, I conceive, by a little, experience, they 

 can at once determine whether any aperture amongst 

 hedges or shrubs, in which animals of this genus live 

 in their wild state, is large enough to admit their 

 bodies ; which to them is a matter of the greatest 

 consequence, whether pursuing or pursued. They 

 have likewise a power of erecting and bringing for- 

 ward the whiskers on their lips, which probably is for 

 the purpose of feeling whether a dark hole be further 

 permeable *." 



" The seal/' says Blumenbach, (s has a very long 

 nerve below the orbit of the eye, consisting of about 

 forty branches, which are distributed to the projecting 

 lip. I have traced many of their terminations to that 

 part of the integuments in which the bulbous roots of 

 their strong whiskers are inserted. I think, however, 

 that the ornithorynchus clearly possesses an organ 

 of touch. In this curious animal, the sense in ques- 

 tion resides in the integuments which cover the 

 expanded portion of its jaws, particularly the upper 

 one ; this part is most copiously supplied with nerves 

 from the fifth pair, and chiefly from its second branch, 

 distributed just in the same manner as they are on 

 the corresponding parts of swimming birds f." 



Sir Everard Home describes the mouth of this 

 animal to be " regularly formed like that of a qua- 

 druped, but projecting beyond it a bill so like that of 

 a duck, that it might almost be taken for it, though 

 it is still more like that of a spoonbill, the middle part 

 being composed of bone, and the whole having a very 

 strong cuticular covering. In the upper mandible of 

 the bill the lip extends for half an inch everywhere 

 beyond the bony part, and is thick and fleshy ; the 

 * Zoonomia, i, 16. t Comp. Anat, 224. 



