INCUBATION OF THE EGG OF THE COMMON FOWL. 



367 



Natural Temperature of Hen. - - In attempting to determine 

 the daily temperature of the hen, special self-registering ther- 

 mometers were fastened to blocks so cut that their upper surfaces 

 were nearly egg-shaped. The lower surfaces of the blocks were 

 broad and flat, so that they could not be easily overturned. 

 One was placed in each of four nests and left for two or three 

 hours, when the reading was made. 



The following table shows the temperatures obtained by this 

 method, during twenty days of incubation. In this as in subse- 

 quent tables, the Roman numerals indicate the serial numbers 

 by which the hens were designated, while those above the columns 

 indicate the day of incubation. 



A second series of readings was made by gently removing 

 the hen from the nest and placing the thermometer in the groin 

 for five minutes. The results are of course, somewhat unsatis- 

 factory, since the excitement of the fowls due to their being 

 removed from the nest, results in a temperature somewhat higher 

 than the normal. 



Natural Temperature of Egg. Since experiments show that 



