FEOG 217 



the anterior end of the omosternum find the epi- 

 sternum. Compare in all respects with the xiphi- 

 sternum. Draw the episternum. Is the ventral 

 portion of the pectoral girdle flexible ? Does the 

 girdle as a whole permit of a very great range 

 of motion? Of how many pairs of bones does 

 the pectoral girdle consist ? Pairs of cartilages ? 

 Of how many median bones ? Median carti- 

 lages ? 



d. The fore limb. — Examine the right fore liipb, and 

 note its division into arm or brachium, fore- 

 arm or antebrachium, wrist or carpus, and 

 hand or manus. Examine the arm - bone or 

 humerus. What is its shape ? How is it con- 

 nected to the pectoral girdle ? Note the enlarged 

 upper end or head of the humerus. How does 

 its surface difPer from that of the rest of the 

 bone ? Extending downward from the head find 

 the deltoid ridge. On what part of the hume- 

 rus is it ? How is it formed ? How far does it 

 extend ? Do you find any other ridges on this 

 bone ? Examine the skeletons of several frogs 

 of the same size. Are the ridges equally promi- 

 nent in all ? How does the lower difl'er from the 

 upper end of the humerus ? In how many direc- 

 tions may the humerus be moved ? Why ? Com- 

 pare with your own shoulder -joint. Draw the 

 humerus. 



Examine the bone, the radio-ulna, of the fore- 

 arm. What is its shape ? Does it appear to be 

 composed of two consolidated bones? What is 

 the shape of the upper end of the radio-ulna? 

 Which is the radius and which the ulna ? Study 



