62 



Table XXV. Average Weight of Eggs and the Phosphoric Acid and Lime 



in Shell and Contents (grams). 



The above data show that the lime in the contents of the egg varies 

 from a little less than .03 grams to over .04 grams, a very small amount 

 to supply all the lime necessary for the formation of bone in the young 

 chick. 



To ascertain the absolute weight of lime in the chick at different 

 stages of the period of incubation, we took eggs from the incubators 

 eleven days and twenty days from the commencement of incubation and 

 determined the amount of lime in the partially developed and fully 

 developed chick. It was soon found that after eleven days of incubation 

 there was practically the same amount of lime in the partially developed 

 chick as there was in the contents of the original egg, but that at the end 

 of the incubation period there was a very decided increase. The eggs 

 used in this part of the work in the June hatch were from the same hens 

 as the eggs analyzed earlier in the season. It was impossible to secure 

 eggs from the same hens for the study of the July hatch, but there is such 

 a wide difference between the average lime content of the fresh egg and 

 that of the young chick at the end of incubation period that it does not 

 seriously affect the results. Unfortunately we were unable to take up the 

 work of determining the lime content of the chicks until so late in the 

 season that we could not study more than one hatch with each incubator. 

 Conseqeuntly, the results obtained are not so reliable and conclusive as if 

 a number of hatches with each method of incubation could have been 

 examined. However, some very interesting facts have been ascertained, 

 and the work will be continued another year. The following table gives 

 the results obtained so far: — 



