376 



On Decrease in the Weight of Eggs. 



XXVIII. — Note o/i the Decrease in the Weight of Eygs a* 

 Incubation advances. By Hugh S. Gladstone, M.A., 

 F.Z.S., .M.B.O.T. 



During the spring of 1903, when picking up Pheasants' 

 eggs which had been laid in precarious places, such as the 

 sides of roadways or near human habitations, I happened 

 to weigh some of them, and was at once struck by the 

 variation in their weight. Thinking that this variation might 

 be caused by the length of time the eggs had been incubated, 

 I had ten newly-laid eggs from ten different hens marked, and 

 weighed them every fourth day. with the following results. 

 I reckoned .'27 grs.= 1 dr. 



This proves that a general decrease in the weight of the egu:s 

 took place whilst incubation was proceeding, the following 

 table shewing the average decrease every fourth day : — 



Variation in weight 

 from first dav. 



gr>. 



-10 

 -21 

 -30 

 -40 

 -49 

 -66 



Fir<t day 



Fourth day 

 Eighth dav 

 Twelfth day 

 Sixteenth day . . 

 Twentieth day . . 

 Twentv-third dav 



