EGERTON, See BRIDGEWATER, ante.
EGG, Ovum. In a great majority of the different kinds of animals, reproduction takes place by means of eggs; in other words, the animals are oviparous. It is only in the mammalia that we find animals truly viviparous; whilst the marsupial quadrupeds and the monotremata form connecting links, in this part of their natural history, between the mammalia which are viviparous in the fullest sense of the term, and the warm-blooded animals (birds) which are oviparous.
To the articles REPRODUCTION and DEVELOPMENT OF THE EMBRYO, we must refer for an exhibition of the differences between oviparous and viviparous reproduction, and of that original and essential agreement in important particulars, which has been strongly asserted in the saying, Omne animal as ore (Every animal is produced from an egg). To the article DEVELOPMENT OF THE EMBRYO also reference must be made for what may be called the history of the E., and the development and uses of its several parts.
The number of eggs varies extremely in different animals, some birds producing only one at a time, or in a year, others twenty or nearly so, whilst the roe of the herring, cod, and many other fishes, contains myriads of eggs. The eggs of sonic animals are enveloped in a gelatinous mass; those of some are joined together, and are laid in a kind of string; those of others are connected together in various ways. For notice of such peculiarities, we must refer to the articles on different classes of animals.
The economical uses of eggs are well known. The eggs chiefly used are those of birds, although the eggs of turtles are also in great repute as an article of food and lux ury, and those of fresh-water tortoises are valued for the oil which they yield. The
birds' eggs chiefly used for food are those of the species commonly domesticated as poultry, and others allied to them—gallinaceous birds and web-footed birds. Of galli naceous birds, the common domestic fowl, the turkey, the peahen, and the guinea-fowl, produce the eggs most generally used and brought to market in different parts of the world; of web-footed birds, the common duck is in this respect the most important, although the eggs of other anatidce are also used for food, and those of some of the other web-footed marine-birds are much sought after by the inhabitants of the wild and rocky shores which they frequent., Thus, the eggs of gulls and guillemots afford an impor tant article of food to the people of St. Kilda, and of some of the Orkney and Shetland islands, as well as to the inhabitants of Iceland and other far northern regions. It is in quest of eggs, as well as of young birds, that the dangers of the most tremendous preci pices are braved by men whom their companions let down by ropes, and who gather the eggs from the rock ledges. The coasts of Labrador are also visited by eggers, who collect the eggs of sea-birds, and carry them for sale to some of the American ports. The eggs of some of the sea-birds of the West Indies are of considerable commercial importance. See EGG-BIRD.