CHAPTER VIII 
MUSCLES AND NERVES 
Muscles 
ae : 
fj} than any other class of animals. Some seem 
ver to be still, and, whether soaring, fluttering, 
running, hopping, climbing, dancing, or swimming, every 
motion is the result of the action of one or more muscles. 
The entire flesh of a bird is divided up into layers 
or bundles of distinct muscles, each having its function,— 
raising, lvering, or in some way moving feathers, eye- 
lids, legs, wings, tail, and other portions of the body. The 
number and intricacy of these muscles can be imagined 
when it is stated that in a goose there are more than twelve 
thousand muscles or parts of muscles immediately be- 
neath the skin, which serve to raise or otherwise move 
the feathers. 
In a penguin the muscles immediately beneath the 
skin are unusually well developed, and for an excellent 
reason. By means of them the water “may be readily 
expelled from the interstices of the plumage so soon as 
the bird quits the water. Were it otherwise, in the low 
temperature of the Antarctic region, which the majority 
of these birds inhabit, their plumage would soon be frozen 
188 
