140 HABITS OF BIRDS. 



upon shelves, the rest were put in baskets, and 1 

 made myself very certain that they were all kept 

 nearly in the same degree of heat they would have 

 had under a hen. I could hardly let the first twenty- 

 four hours pass without attempting to ascertain the 

 effect produced upon the eggs ; and I broke two, in 

 which I had the pleasure of seeing the little heart, by 

 this time developed, already begin to beat, and the small 

 drop of blood, sufficient to fill it, entering and de- 

 parting. This was a sight which a naturalist could 

 not soon be tired of were it to last much longer than 

 its usual time of six or eight minutes. For the next 

 four or five days I had the satisfaction of being able 

 to keep up the uniformity of temperature, and of 

 observing the progress made by the embryos in the 

 eggs, some of which I broke daily to ascertain this. 

 I even began at length to feel regret in breaking 

 them, under the notion that I should lose so many 

 chickens out of my number. 



"The eggs of this as well as those of a great 

 many other broods began, at the eighth or tenth 

 day, to disappoint my expectations. Till then I had 

 found in the eggs which I broke the chickens as 

 forward as I could wish ; the scene soon changed, 

 and the odour diffused over the oven informed me 

 that some of the eggs, at least, had begun to be 

 tainted* These, indeed, were easily distinguished 

 from the sound ones, by the tainted matter in some 

 instances having burst through, and, in others, oozed 

 out of the pores of the shell. I had these tainted 

 eggs all carefully taken out ; but as they every day 

 increased in number, I concluded that some accident 

 had occurred fatal to them all ; for though the chicks 

 in some of them were formed, and even feathered, 

 they were all dead. 



" As I had succeeded in bringing these chickens 

 through two-thirds of the regular period of hatching 



