372 THE GAME PRESERVER'S GUIDE. 



A box, with a lid to it, from a foot to eighteen inches square, 

 should be provided for each, hen, and when the "broodi- 

 ness" is fully established, put some hay in it sufficient to 

 make a comfortable nest, and in this place the eggs. The 

 lid should have a number of holes cut in it with a centre- 

 bit, for ventilation, and should be capable of being fastened 

 down with a hasp and padlock in the usual way, which will 

 allow the box to be safely left in places where it might 

 otherwise be liable to interference. If several hens are 

 sitting at the same time, the eggs may be examined at the 

 end of the first week while the hens are feeding, and then if 

 one-quarter or one-fifth are addled, which is about the usual 

 proportion, they are removed, and making four nests into 

 three, or five into four, according to the numbers, one hen is 

 set at liberty for another hatch. The mode of distinguishing 

 the addled eggs is simple enough. Take an egg and hold it, 

 with the hand closed round it, between the eye and a strong 

 light, when if it is good a dark speck will be visible at the 

 end of five or six days from the commencement of sitting. 

 A little practice is required in this operation ; but by look- 

 ing at a few with care the difference is soon detected. 

 Nevertheless, it is well to depend upon an experienced 

 friend in the first instance. Pheasant eggs are hatched in 

 twenty-four days; those of partridges in twenty-one. 



Every hen bird naturally leaves her nest daily for a 

 longer or shorter period in order to attend to the calls of 

 hunger, by which another purpose is served connected with 

 the due aeration of the eggs. On the average, three-quarters 

 of an hour will be the time during which the hens are off, 

 and this is sufficient to lower the temperature very con- 

 siderably. As a consequence, the portion of air contained in 

 the cell at the end of each egg contracts as it cools, and 

 draws in through the pores of the shell a fresh supply, which, 

 mixing with the whole quantity, affords fresh oxygen once 

 in each day. When the heat is again raised, a part of the 

 whole is forced out again by its expansion, and so day by 

 day a kind of partial respiration is carried on essential to 

 the due performance of the act of incubation, and necessarily 

 imitated in artificial machines by lowering the temperature 

 for an hour every day. If the hens are close sitters they 



