THE EGG 21 



PER CENT. 



Magnesium (MgO) 2.07- 2.11 



Iron (Fe 2 O 3 ) 1.19- 1.45 



Phosphoric acid, free (P 2 O 5 ) 5.72 



Phosphoric acid, combined 63.81-66.70 



Silicic acid : 0.55- 1.40 



Chlorine Traces. 



GENERAL COMPOSITION OF THE ALBUMEN 



Water 80.00-86.68 



Solids 13.22-20.00 



Albumens 11.50-12.27 



Extractives 0.38- 0.77 



Glucose 0.10- 0.50 



Fats and Soaps Traces 



Mineral salts 0.30- 0.66 



Lecithins and Cholesterin Traces. 



ANALYSIS OF THE MINERAL ASH 



Sodium (Na 2 O) 23.56-32.93 



Potassium (K 2 O) 27.66-28.45 



Calcium (CaO) 1.74- 2.90 



Magnesium (MgO) 1.60- 3.17 



Iron (Fe 2 O 3 ) 0.44- 0.55 



Chlorine (Cl) 23.84-28.56 



Phosphoric acid (P 2 O 5 ) 3.16- 4.83 



Carbonic acid (CO 2 ) 9.67-11.60 



Sulphuric acid (SO 3 ) 1.32- 2.63 



Silicic acid (SiO 2 ) 0.28- 0.49 



Fluorine (Fl) Traces. 



The shell consists of an organic matrix of the nature of keratin 

 impregnated with lime salts: calcium and magnesium carbonates 

 about 97 %, calcium and magnesium phosphates about 1 %, 

 keratin and water about 2 %, trace of iron. 



The shell-membrane and the vitelline membrane are stated 

 to consist of keratin or a closely allied substance. 



Formation of the Egg. The organs of reproduction of the 

 hen are the ovary and oviduct of the left side of the body. Al- 

 though the right ovary and oviduct are formed in the embryo 

 at the same time as those of the left side, they degenerate more 

 or less completely in the course of development (see Chap. XIII), 

 so that only functionless rudiments remain. This would appear 

 to be correlated with the large size of the egg and the delicate 



