Columbia Encyclopedia

Search results

45 results found

ovum

(Encyclopedia)ovum ōˈvəm [key], in biology, specialized plant or animal sex cell, also called the egg, or egg cell. It is the female sex cell, or female gamete; the male gamete is the sperm. The study of the ovu...

butterfly

(Encyclopedia)butterfly, any of a large group of insects found throughout most of the world; with the moths, they comprise the order Lepidoptera. There are about 12 families of butterflies. Most adult moths and but...

coal

(Encyclopedia)coal, fuel substance of plant origin, largely or almost entirely composed of carbon with varying amounts of mineral matter. Coal is found in beds or seams interstratified with shales, clays, sands...

atmosphere

(Encyclopedia)CE5 Atmosphere atmosphere [Gr.,=sphere of air], the mixture of gases surrounding a celestial body with sufficient gravity to maintain it. Although some details about the atmospheres of other plane...

bat

(Encyclopedia)bat, winged mammal of the order Chiroptera, which includes 900–1,000 species classified in about 200 genera and 17 families. Bats range in size from a wingspread of over 5 ft (150 cm) to a wingsprea...