Page:Collier's New Encyclopedia v. 03.djvu/549

LEFT EGG 477 EGGLESTON kindness the confidence of the natives. In 1736 he returned to Copenhagen, where he was made a bishop and di- rector of the Greenland missions. He died in 1758. His son, Paul Egede, born in 1708, followed in his father's footsteps, became Bishop of Greenland, and died in 1789. EGG, a mass or speck of protoplasm developed in the females of all but the lowest animals and when impregnated with the corresponding substance of the opposite sex capable of producing or- ganisms like the parents. The egg throughout the animal kingdom is, in the last analysis, one single perfect cell, in which there are four parts, the cell wall, the cell substance, the nucleus and the nucleolus. The eggs of animals lower than the reptile have usually only three parts, viz., the germinal spot or dot, the germinal vesicle, and the vitel- lus or yolk; the first being contained in the vesicle, and that again in the yolk. Such eggs are usually of microscopic size and before being impregnated do not differ from any other cell or from the whole of a single-celled animal. The parts of an egg named are in general terms the same as those used for cells, but each part has its special name. Thus the nucleolus, the smallest recognizable constituent, is called the germinal spot or spot of Wagner because it was dis- covered by Wagner in 1836. The nu- cleus is called the germinal vesicle or vesicle of Purkinje because it was dis- covered by Purkinje in 1825. The com- mon cell substance or protoplasm is called^ the vitellus or yolk and the cell wall is called the vitelline membrane. Some eggs have other regular constitu- ents as, for instance, a quantity of col- ored albumen or food yolk, like that con- stituting the yellow of a hen's egg. Sec- ondly, a quantity of colorless albumen, called the white of the egg, which usual- ly coagulates when warm and is used in photography for preparing the paper. Thirdly, the egg-shell which, especially in birds, consists of a membrane coated with carbonate of lime and in the eggs and consistency of parchment. The white and the yellow of eggs are in- closed in the shell wall which, as it in- creases in size, attains a special thick- ness and toughness and is called the egg-pod or putamen. Under the term egg is included the ovum of every kind of mammal ; but in general the English term egg is used only of those animals that do not pro- duce their young alive. All animals dif- ferentiated by sex lay eggs. Those in which the egg passes out of the body and is hatched outside are called oviparous, those in which the egg remains inside the body to hatch are called ovovivipar- ous; those whose eggs are retained in connection with the parent by means of a placenta and an umbilical cord so that the young are brought forth alive are called viviparous. Through repeated di- vision of the germinal vesicle a multi- tude of cells is formed out of which the embryo is developed. In the case of birds, reptiles, and the majority of in- sects, the young is nourished in the egg by means of the albumen there stored so that after the egg is laid the develop- ment continues till the animal hatches out. Eggs the whole of whose yolk makes up into the body of the embryo are called holoblastic. Others with food yolk which does not undergo seg- mentation are meroblastic. Birds' eggs are meroblastic. All birds lay eggs and so also do most reptiles, amphibians, and fishes; insects, crustaceans, and mol- lusks are oviparous. In this class are included the ornithorhynchus and echidna. The eggs of amphibians are usually found in floating glutinous mas- ses. The eggs of fishes are popularly known as roe or spawn. Eggs vary vastly in size. The ova of mammals are usually spherical and mi- croscopic. The human ovum is among the smallest known, being a minute spherical body from 1-120 to 1-125 of an inch in diameter, while the largest known egg is that of the extinct ele- phant bird Epyomis Maximus of Mada- gascar, the shell of which had a capa- city of about two gallons and was six times the size of the egg of the ostrich. The eggs of birds, especially of fowls and some reptiles, as turtles, are com- monly used for food. A hen's egg of good size weighs about 1,000 grains, of which the white constitutes 600, the yolk 300, and the shell 100. There are generally 10.7 parts shell, 11.9 parts al- bumen, 12.8 parts fat, .7 parts salt, and 63.9 water. Besides their use as a food, hen's eggs are used in the technical arts, the albumen in which they are so rich serving in dying, manufacture of leather, and various other purposes. The science of birds' eggs is called oology. EGG, one of the Hebrides Islands. EGGLESTON. EDWARD, an Ameri- can author; bom in Vevay, Ind., Dec. 10, 1837. In fiction he has achieved celeb- rity with stories of life in southern In- diana in pioneer days. His works include : "The Hoosier Schoolmaster": ''The Cir- cuit Rider"; "Roxy"; "The Graysons ; "The Faith Doctor"; "The „^Hoosier 31 — Vol. Ill — Cjrc
 * f reptiles possessses the appearance