I.] THE FROG. 73 



Look for similar perforations in the other bones 

 examined. 



8. Pull the limb out straight, plantar surface down- 

 wards, as directed for the anterior appendage. 

 The tibia and hallux are pre-axial; the fibula 

 and little-toe post-axial. 



c. The tarsus. 



Its proximal elements are seen as two elongated 

 bones (separate in the middle but confluent at 

 their cartilaginous extremities) in articulation with 

 the ankylosed tibia and fibula; the pre-axial, or 

 tibial, of these is the astragalus ; the post-axial or 

 fibular, the calcaneum. 



d. The digits. Five in number ; the internal one the 

 shortest, the fourth the longest. Their compo- 

 sition — 



a. The first, or hallux (the most internal) ; a me- 

 tatarsal bo7ie, followed by two phalaiiges. 



/?• The second : same as a, but longer. 



y. The third : a metatarsal bone with three pha- 

 langes. 



8. The fourth : a metatarsal bone and four pha- 

 langes. 



f. The fifth : like the third, but a little shorter. 



e. The tarsus and calcar. 



Remove the middle portion of the foot-skeleton, 

 to include the apposed ends of the astragalus and 

 calcaneum and the metatarsals ; treat with alcohol 

 and oil of cloves as previously directed, and ex- 

 amine under a low power. 



