THE WONDERS OF A HEN'S EGG.

Thames Star, Volume VII, Issue 1882, 14 January 1875, Page 3

THE WONDERS OF A HEN'S EGG.

The following interesting observations on the change that occur from hour to hour during the incubation of the hen'a egg are from " Saturn's Reflections:"— The hen has scarcely sat on her eggstwelve hours before some lineaments of the head and body appear. The heart may be seen to beat at the end of the second day; it has at itiat time soraewhat'the form of a horse shoe, but no blood yet appears. At the end of two days two vessels of blood are to be distinguished, the pulsation of which is visible ; one of these is the ventricle, and the oth<*r 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 afterwards in the ventricle. At the end of seventy hours the wings are distinguishable, and on the head two bubbles are seen for the brain, one for the bill, and two for the fore and hind part of the head. Tpvrard the end, of the forth day the two auricles already visible draw nearer to the heart than before. The liver appears towards the fifth day. At the end of seven hours more the lungs and the stomach become visible, and four hours afterwards the intestines and lines of the upper jaw. At the one hundred and forty-forth hour two ventricles are visible, arid 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 one hundred and nineteenth hour ofincubationthobill opens, and the fle»h appears on 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 risible, as well as the yall bladder. The bill becomes green in the end of two hundred and thirty-six hours ; and if the chicken be taken out of its covering it evidently moves itself. At the two hundred and sixty forth hour the eyes appear. At the two hundred and eighty-eigh h the *ibs are perfect, At the three hundred and thir(y-first the spleen draws near the stomach and the lungsto the chest. At the end of three hundred and fifty-five hours the bill frequently opens and shuts ; and at the end of the eighteenth day the first cry of the chicken is heard. It af erwards gets more strength and grows continually, till nt length it is enabled to set itself free from its confinement. [FTow are these calculations affected when hatching is done by steam ?]