INCUBATION. 



177 



to turn round, and thus to peck a circle, as seen 

 in the above illustration, and breaks a circle 

 around the large end of the shell, admitting the 

 air by degrees, until it becomes gradually pre- 

 pared to extricate itself. A rash attempt to 

 help them by breaking the shell, particularly in 

 a downward direction toward the smaller end, 

 is often followed by a loss of blood, which can 

 ill be spared, and death ensues. 



The following account of the wonderful 

 changes which an egg undergoes in hatching, 

 from the first day till its final exclusion, is par- 

 ticularly interesting, and is taken from an En- 

 glish journal. By means of the Eccaleobion 

 and hatching-ovens, many interesting facts have 

 been discovered, and are described with great 

 minuteness. 



" The hen has scarcely sat on her eggs twelve 

 hours before some lineaments of the head and 

 body of the chicken appear. The heart may 

 be seen to beat at the end of the second day ; 

 it has at that time somewhat the form of a 

 horseshoe, but no blood yet appears. At the 

 end of two days, two vesicles of blood are to be 

 distinguished, the pulsation of which is very 

 visible ; one of these is the left ventricle, and 

 the other the root of the great artery. At the 

 fiftieth hour, one auricle of the heart appears, 

 resembling a noose folded down upon itself. 

 The beating of the heart is first observed in the 

 auricle, and afterward in the ventricle. At the 

 end of seventy hours, the wings are distinguish- 

 able ; and on the head two bubbles are seen for 

 the brain, one for the bill, and two for the fore 

 M 



and hind part of the head. Toward the end of 

 the fourth day, the two auricles already visible 

 draw nearer to the heart than before. The 

 liver appears toward the fifth day. At the end 

 of a hundred and thirty-one hours, the first vol- 

 untary motion is observed. At the end of seven 

 hours more, the lungs and the stomach become 

 visible ; and four hours afterward, the intestines, 

 the loins, and the upper jaw. At the hundred 

 and forty-fourth hour, two ventricles are visible, 

 and two drops of blood instead of the single one 

 which was seen before. The seventh day, the 

 brain begins to have some consistency. At the 

 hundred and nineteenth hour of incubation, the 

 bill opens, and the flesh appears in the breast. 

 In four hours more, the breast-bone is seen. In 

 six hours after this, the ribs appear, forming 

 from the back, and the bill is very visible, as well 

 as the gall-bladder. The bill becomes green at 

 the end of two hundred and thirty-six hours ; 

 and if the chicken be taken out of its covering, 

 it evidently moves itself. The feathers begin 

 to shoot out toward the two hundred and for- 

 tieth hour, and the skull becomes gristly. At 

 the two hundred and sixty-fourth hour, the eyes 

 appear. At the two hundred and eighty-eighth, 

 the ribs are perfect. At the three hundred and 

 thirty-first, the spleen draws near the stomach, 

 and the lungs to the chest. At the end of three 

 hundred and fifty-five hours, the bill frequently 

 opens and shuts ; and at the end of the eight- 

 eenth day, the first cry of the chicken is heard. 

 It afterward gets more strength and grows con- 

 tinually, till at length it is enabled to set itself 

 free from its confinement. 



"In the whole of this process we must re- 

 mark that every part appears at its proper time ; 

 if, for example, the liver is formed on the fifth 

 day, it is founded on the preceding situation of 

 the chicken, and on the changes that were to 

 follow. No part of the body could possibly ap- 

 pear either sooner or later without the whole 

 embryo suffering; and each of the limbs be- 

 comes visible at the first moment. This ordi- 

 nation, so wise and so invariable, is manifestly 

 the work of a Supreme Being ; but we must still' 

 more sensibly acknowledge His creative powers, 

 when we consider the manner in which the 

 chicken is formed out of the parts which com- 



