COLLATERAL READING 371 



yolk will rise until the germinal disc comes in contact with the shell 

 membrane. It will then become dry by evaporation and adhere to 

 the membrane. If the egg is then turned the germ will be killed. 



(4) Make a drawing of the longitudinal section of the egg, showing: 

 (a) The shell and its pores. (6) The two shell membranes turned 

 back from the shell, (c) The air-space, (d) The three layers of albu- 

 men, (e) The vitelline membrane surrounding the yolk. (/) The 

 vitellus contained within the vitelline membrane, (g) The white yolk 

 and the dark yolk, showing its concentric layers, (h) The germinal 

 disc, (t) The chalaza ("hammock cords"). 



COLLATERAL READING 



Farmers' Bulletins Nos.: 



287. Poultry Management. 

 51. Standard Varieties of Chickens. 

 64. Geese and Ducks. 

 182. Poultry as Food. 

 200. Turkeys. 

 225. Turkeys, pp. 21-25. 

 236. Incubation and Incubators. 

 281. Incubation, pp. 24-28. 

 U)9. Incubation, pp. 24-26. 

 128. Eggs and Their Use as Food. 



Poultry-House Construction. Bulletins: No 225, pp. 



27-31; No. 227, pp. 28-32. 

 Poultry Appliances. Bulletins: No. 244, pp. 25-29; No. 



316, pp. 30-32; No. 317, pp. 28-32. 

 Feeding. Bulletins: No. 84, pp. 19, 20; No. 97, pp. 16, 

 17; No. 122,pp. 25, 26; No. 225, pp. 26, 27; No. 305, 

 p. 28. 



122. Weight of Eggs of Different Breeds, pp. 24, 25. 

 114. Floor Space Necessary per Hen, pp. 18, 19. 



Preserving Eggs No. 103, pp. 17, 18; No. 273, pp. 17-19; 



No. 296, pp. 29-31. 



Cyclopedia of American Agriculture, Vol. Ill, pp. 525-587, and 

 Index. 



