B2 A MANUAL OF ZOOLOGY 



with the others and note rwhether they are bones or 

 car]tilage. 



The Fore Limb — Notice that it is made up of four 

 parts; the humerus, radio-ulna, carpus, and manus. Make 

 a drawing of the humerus after making a careful study 

 of it. The proximal end of the humerus is enlarged to 

 form the head and articulates with the pectoral girdle 

 at the glenoid cavity. Observe a prominent ridge, the dei- 

 toid ridge, on the dorsal sid€. How do the two ends of, 

 the ridge differ? Are both ends of the humerus alike? 

 What is the shape of the radio-ulna? What would suggest 

 this name for the bone? The olecranon process is back 

 of the elbow joint. What movements are possible in the 

 elbow joint? How many, and what is the arrangement of 

 the carpal bones? Note the position of the hand on a 

 living frog. Compare the movements possible in the wrist 

 of the frog with those of your own. Examine the meta- 

 carpals. Study the phalanges. Notice carefully tbe pollex 

 or thumb, and point out any differences between this and 

 the fingers. 



The- Pelvic Girdle — Compare this with the pectoral 

 girdle, in shape, and the direction in which it extends; 

 What Is its attachment to the axial skeleton? Make out 

 the following bones which are more or less fused to make 

 up the girdle: the ilium, which runs nearly parallel to the 

 urostyle, the ischium, which forms the greater part of the 

 posterior half, and the pubis, which forms the ventral 

 portion. Note carefully the shape of each of these parts. 

 Find the acetabulum, the cavity into which the femur fits. 

 Make a drawing showing a side view of the girdle. 



The Hind Limb — In what way does the femur differ 

 from the humerus? Compare the range of motion of the 

 femur with that of the humerus. Give your reasons for 

 any difference. Compare the tibio-flbula with the corre- 

 sponding parts in the fore limb. Find the tarsus. Note 

 the astragulus, and the calcaneum. Note the direction 

 of motion possible in the bones of the hind foot. Do you 

 find a patella? Make a drawing of the bones of the hind 

 leg. Compare -the skeleton of the frog with as many 

 other skeletons as you bave at hand. 



