114 PRACTICAL ZOOLOGY. 



toralis major, lying in the angle between the keel of 

 the breastbone and the body of the breastbone ; prove 

 its action, this time holding the pigeon right side 

 up. Compare these two muscles in size, and in the 

 amount of work they have to do. The smaller muscle 

 is the pectoralis minor. The hinder attachment of 

 each of these muscles is called its origin ; and the 

 place of attachment of the tendon to the wing-bone is 

 the insertion. 



23. Observe the fold of skin extending across the angle 

 between the arm and forearm ; dissect away the skin, 

 and find a membrane within the skin-fold. 



24. Observe the muscles connecting the hinder edge of 

 the breastbone and the pelvis (which were cut through 

 in opening the abdomen) ; these are the abdominal 

 muscles. How does the bird perform the act of 

 breathing ? Compare the bird, snake, frog, and man 

 in their modes of breathing. 



25. Bend the leg up close to the body, to the position of 

 perching ; what effect does this bending of the leg 

 have on the toes ? How does the bird stay securely 

 on the perch when asleep? Dissect the leg to find 

 the mechanism by which the toes are clenched as the 

 leg is bent. 



26. Clean away as much as possible of the soft tissues, and 

 keep the skeleton for later study. 



27. Dissect out the tongue, and compare it with the tongue 

 of the snake. The voice is produced in the lower 

 part of the windpipe, instead of in the upper part, as 

 in man. 



