DIGESTION, ASSIMILATION, NUTRITION 223 



12. Describe the location and appearance of the gizzard. 



13. What is the function of the gizzard? How does it do its work? 



14. Enumerate the digestive organs in the order in which the food 



passes through. 



15. What is the oesophagus? 



16. Where is the crop located? What is its function? 



17. Where is the stomach located and what is its function? 



18. Describe the process of assimilation. 



19. Describe briefly the process of nutrition. 



20. Describe the course that the blood takes in passing once through 



the circulatory system. 



References. — ^United States Farmers' Bulletins: 142, The Principles 

 of Nutrition and Nutritive Values of Foods; 506, Food of Some Well 

 Known Birds of Forest, Farm and Garden. 



