12 MAINE AGRICULTURAL EXPERIMENT STATION. 10,02. 



EXPERIMENTS IN INCUBATION. 

 G. M. Gowell. 



TREATMENT OF EGGS BEFORE INCUBATION. 



Close Cases vs. Light and Air. 



Some of the influences which may affect the strength of the 

 germs of eggs that are kept for some time before being incubated, 

 were studied by keeping part of them shut up in the dark, in 

 ordinary egg cases for ten days, while another lot from the same 

 hens was kept spread out in open pans, in the light, on a stand 

 beside the darkened case. This gave both lots practically the 

 same temperature of 62° F. They were turned daily. It was 

 unfortunate that the eggs were running low in fertility when all 

 of the tests which are reported in this Bulletin were being made, 

 but the hens had been laying very heavily for a long time, and 

 that probably accounts for their low fertility. Two pens of hens 

 were selected and the eggs of each individual were divided evenly 

 into two lots by alternating them in the order in which they were 

 laid. This was readily done as trap nests are used with all our 

 birds and all the hens are banded and numbered. By taking 

 each hen's eggs as laid and dividing them by placing alternate 

 eggs in the same lots, a fair division was secured by which it was 

 hoped to avoid the difficulties which might arise from the physi- 

 cal changes which are liable to take place in laying hens. 



The eggs were laid between May 25th and June 2d. After 

 160 were obtained, they were kept for the next ten days, until 

 June 1 2th and then put together into the same incubator, each 

 egg being marked with the number of the hen that laid it, the 

 date and its class. 



The following tables show some of the details of the work and 

 the results of the test. 



