144 



JouEXAL OF THE MiTciiELL SociETY [September 



TABLE II— ANALYSES OF AIR 



By way of comparison with artificial incubation the results are re- 

 ported in the case of eight hens, which probably show a record below 

 normal, because one hen by leaving her nest caused a heavy loss, but 

 the very low figures, 4.8%, for loss from death in shell after the 

 eighteenth day, is significant, and probably presents a not unreasona- 

 ble standard for an incubator operated under perfect conditions. 



The tables are self-explanatory. Manifestly they present oppor- 

 tunities for numerous inaccuracies. For instance, it is evident that 



