The Senses 219 
tongues and ample membranes of the mouth, doubtless 
possess this sense to a considerable degree, while in birds 
which are exclusively fish-eaters we may expect to find 
taste least developed, the character of their food pre- 
cluding all need for this faculty. 
But from no bird is taste entirely absent, as we may 
easily see by presenting some nauseous insect, which 
will be instantly rejected with very evident signs of dis- 
gust, the bird wiping its bill on a branch and shaking 
its head violently. 
The sense of feeling, although much deadened by the 
feathery and horny character of a bird’s integument, is 
most active at the tip of the tongue and the beak. At 
the base of the feathers, especially those of the wings and 
tail, tactile nerves are found, so that even a touch on the 
tips of the feathers awakens a response in the nervous 
system. 
The delicacy of the tactile touch is remarkable in those 
long-billed birds which seek their food in the muddy 
bottom of shallow water, detecting by means of their 
sensitive bills the presence of worms and _ snails,—aided 
little or not at all by eyesight. In the woodcock and 
apteryx this dependence on the senses of touch and smell 
has even wrought a change in the position and character 
of the eyes. The upper mandible of the woodcock is 
probably unique in being so sensitive and mobile that the 
distal third can be curved some distance upward, the base 
of the two mandibles remaining close together. This is 
an admirable provision by which, when the bird has driven 
its beak deep down into the moist soil, it may feel about 
