BUSY FROM SUNSET TO SUNRISE 



farmer by the destruction of mammal and insect pests. In- 

 asmuch as their regular working hours are from sunset to 

 sunrise, they wage successful war on the nocturnal mammals 

 which remain quiet during the daytime in order to escape 

 hawks and other daylight enemies. 



SKELETON OF A BIRD OF PREY. (BALD EAGLE.) 



1. Upper mandible. 



2. Lower mandible. 



3. Hyoid. 



4. External nostril. 



5. Orbit. 



G. Occiput. 



7. Cervical vertebrae. 



8. Clavicles. 



9. Coracoid. 

 10. Ulna. 



21. Digits of foot. 



11. Radius. 



12. Carpals. 



13. Metacarpals. 



14. Digits. 



15. Sternum. 



16. Keel of sternum. 



17. Pelvis. 



18. Fibula. 



19. Tibia. 



20. Tarsus. 



