SECT. l] 



PHYSICO-CHEMICAL SYSTEM 



253 



large, but they were invariably found. Another series of figures show- 

 ing the rise in calorific value during the course of the year and the 

 transition fi-om male to female eggs is given in Table 8. Here also 

 the increase is unmistakable. Within one clutch, also, the water- 

 content of the second egg is lower and the calorific value higher than 

 the first egg, which fits in very well with the fact that under normal 



Date 



May 26 



28 



June 7 



15 



26 



July 3 

 5 



15 

 17 

 23 

 25 



2 



4 

 13 

 25 



15 



17 



29 



I 



Aug. 



Sept. 



Nov. 

 Dec. 



Table 7. Effect of sex on pigeon's eggs. 



Female Turtur orientalis x Streptopelia alba, no. 410 for 191 2. 



% wet weight % dry 



Analysed Weight t ^ ^ weight 



or in- of Pro- Extrac- ale- Calories 



cubated yolk Lipoid tein tives Ash Water sol. per egg Sex 



An. 2-330 18-32 25-44 5-28 4-85 5701 72-65 7405 — 



An. 2-660 17-54 25-63 5-25 2-62 54-82 72-45 8990 — 



Inc. — — — — — — — — Male 



Inc. — — — — — — — — Male 



Inc. — — — — — — — — Male 



An. 2-026 16-49 26-00 3-63 2-43 56-05 71-95 6714 — 



An. 2-330 19-18 26-55 3-75 1-93 5522 72-27 7881 — 



Inc. — — — — — — — — Male 



Inc. — — _____ _ Male 



An. 2-422 17-82 25-88 3-82 I -80 55-84 72-42 8061 — 



An. 2-720 18-88 25-96 3-86 1-81 55-33 72-45 9296 — 



Inc. _______ _ Male 



Inc. — — — — — — — — Male 



Inc. — — — — — — — — Male 



Inc. — — — — — — — — Female 



Inc. — — — — — — — — Female 



Inc. — — — — — — — — Female 



An. 2-700 21-40 — — — 55-45 73-17 9323 — 



An. 2-715 21-63 — — — 55-39 73-02 9383 — 



Table 8. Eggs from the same female Streptopelia risoria (1914). 



Date 



Weight of yolk Energy in cals. 



