THE ENGLISH SPARROW. 221 



and with, a knife blade pushing the flesh away from the 

 skin. At the anterior end of the first cut make a circu- 

 lar cut through the skin, about the base of the neck. 

 Then carefully draw the skin of the neck forward over 

 the head, wrong side out, and fasten it with a tack in 

 front of the beak. While doing this, observe the position 

 assumed by the retracted neck, and note again how much 

 the feathers contribute to the beauty of the bird's outline, 

 and improve its form for rapid passage through the air. 

 Draw the skin out laterally on each side of the first 

 median cut, and fasten it away from the sides of the 

 body. 



Pass a tube into the esophagus, and inflate the crop, 

 a capacious expansion of the esophagus at the base of 

 the neck. Tie a string about the esophagus to keep the 

 crop inflated, for convenience in dissecting off the fat and 

 integument which cover it. 



Observe on each side of the neck a vein (the jugular 

 vein), usually filled with blood, and dark-colored, and 

 close beside it a white nerve (the vagus nerve). 



I. Removal of the Body Wall. On the median line of 

 the breast observe the ventral edge of the sharp ridge 

 (or keel) of the sternum, and on either side of it the 

 thick muscles which cover the sternum. Posterior to the 

 sternum, the internal organs are covered only by the thin 

 wall of the abdomen. Sever the muscles from the keel 

 by a single longitudinal cut on each side of it, keeping 

 the knife close to the bone. Continue the cuts laterally 

 around the posterior edge of the sternum, severing the 

 attachment (origin) of a great flap of muscle. Lift up 

 the loosened posterior end of this great muscle, and 

 observe it separating from a smaller muscle, which has 

 its origin in the angle between the horizontal part of 

 the sternum and the keel. The larger muscle is the 

 pectoralis major; the smaller one, the pectoralis minor. 



