876 



GENERAL METABOLISM 



[PT. Ill 



arrived at by Aggazzotti, who studied the water loss from hen's eggs 

 at sea level, and at the high-altitude research station at Col d'Olen. 

 He found that at a height of 250 metres above sea level the eggs lost 

 more water each day than at Turin (sea level), exactly contrary to 

 what took place in the case of the adult animals, which lost more 

 water each day at Turin than at Col d'Olen. There was evidently 



Gmoj 



0.6 





0.4 



f 0.3 

 •o 



t 0.2 



PcpoenL 



40 50 60 



Humidity 



100 



• Whole series of experiments. + Eggs kept above 38-8'' 



O Eggs measured every two days. o Eggs kept below 38-8" 



* Eggs kept at room temperature. 



Fig. 224. 



no regulatory mechanism in the hen's egg, and Aggazzotti compared 

 the initial unprotected state of the egg as regards water loss with 

 the assumption of homoiothermicity which takes place during de- 

 velopment. 



Interesting experiments on the evaporation rate of hen's eggs have 

 been carried out by Dunn. Individual eggs of White Leghorn breed 

 gave evidence of great variations in the rate at which they lost water. 

 The data for the effect of incubation, presence of living embryo, etc.. 



