THE PIGEON. 109 



there be such; examine the "down" with a micro- 

 scope. 



4. Pick a small part of the breast, and study one of the 

 pin-feathers. How does it differ from the feathers 

 already examined ? 



5. Feathers correspond to the hairs of mammals; there 

 are muscles in the skin of the pigeon, by the action 

 of which the feathers may be raised, as when the 

 bird is angry, or when taking a dust-bath, just as 

 there are muscles in the skin of a dog or cat, or in 

 the human scalp, by which the hair is made to stand 

 on end. 



6. Study the arrangement of the feathers; do feathers 

 grow on all parts of the body ? a fledgling shows this 

 point well. Push aside the feathers along the line of 

 the ridge of the pigeon's breastbone and examine the 

 skin ; do feathers grow here ? Look for other un- 

 feathered areas. Note how the feathers overlap. 



7. Pick the feathers from one 3ide of the pigeon, just to 

 the middle line ; lay the bird on the feathered side, 

 and make a drawing, showing (1) the outline of the 

 feathers ; and (2) the outline of the body within. 



DISSECTION OF THE PIGEON. 



Pluck the pigeon before dissecting it ; dipping the bird 

 in hot water makes this easier. 



1. Insert a tube into the mouth and inflate the crop, 

 compressing the neck to prevent the escape of the air. 

 Note the shape of the crop. 



2. Beginning at the posterior end of the breastbone, cut 



