66 



On looking over the above table it will be seen that the averugr 

 lime content of chicks got by different methods of incubation was lower 

 in June than in July, but in both months the chicks from the hen show 

 the largest amount. There is apparently no connection between the 

 amount of lime absorbed by the chick and the amount of carbon dioxide 

 surrounding - the egg during" incubation. It has been found that large 

 amounts of carbon dioxide are given off from the egg itself during incuba- 

 tion, and it is very probable that the gas from this source would have a 

 greater dissolving effect upon the carbonate of the shell than that in the 

 surrounding atmosphere. This would be true, because it is acting in the 

 presence of liquid moisture. 



While we do not wish to draw any definite conclusion on the com- 

 paratively small amount of work which has as yet been done, still we 

 think it worthy of note that there appears to be some relation between 

 the lime content of the chick and its vitality, as indicated by the per cent, 

 of chicks alive at the end of four weeks. Where lamp fumes were used 

 there is an apparent exception to this, as the percentage vitality is low. 

 This may be explained, however, by the fact that wherever this method of 

 incubation has been used the percentage hatch is low ; but, at the same 

 time, these chicks are always strong and vigorous. It may also be 

 noted that the Continuous Hatcher gave chicks low in lime, and of a 

 high vitality, yet, while a large percentage of these chicks lived through 

 the four weeks' period, they did not prove to be thrifty, thus further 

 bearing out our previous tentative statement, that there is a marked 

 relationship between lime content and vitality. 



We are not prepared, with the insufficient data which we have at 

 hand, to give the above hypothesis with reference to the relationship 

 between lime content and vitality as a definite conclusion, nor to state 

 what conditions in incubation will cause the maximum absorption of 

 lime; but we feel that the point is worthy of further study. 



