Demosponge

The Demospongiae are the largest class in the phylum Porifera. In fact, the demosponges include 81% of all species of sponges with nearly 7,000 species worldwide (World Porifera Database). They are predominantly leuconoid in structure. Their "skeletons" are made of spicules consisting of fibers of the protein spongin, the mineral silica, or both. Where spicules of silica are present, they have a different shape from those in the otherwise similar glass sponges.

The many diverse orders in this class include all of the large sponges. Most are marine dwellers, but one order (Spongillida) live in freshwater environments. Some species are brightly colored, with great variety in body shape; the largest species are over 1 m (3.3 ft) across. They reproduce both sexually and asexually.

Classification and Systematics

Sponge cake

Sponge cake is a cake based on flour (usually wheat flour), sugar, and eggs, and is sometimes leavened with baking powder. It has a firm, yet well aerated structure, similar to a sea sponge. A sponge cake may be produced by the batter method or the foam method.

Cake made using the batter method is known as a butter or pound cake in the U.S., while in the U.K. it is known as Madeira cake or Victoria sponge cake. A cake made using the foam method is known as a sponge cake or, in the U.K., also as whisked sponge. These forms of cake are common in Europe, especially in French patisserie.

The sponge cake is thought to be one of the first of the non-yeasted cakes, and the earliest attested sponge cake recipe in English is found in the book by the English poet Gervase Markham, The English Huswife, Containing the Inward and Outward Virtues Which Ought to Be in a Complete Woman (1615). Though it does not appear in Hannah Glasse's The Art of Cookery made Plain and Easy (1747) in the late 18th century, it is found in Lydia Maria Child's The American Frugal Housewife (1832) indicating that sponge cakes had been established in Grenada in the Caribbean, by the early 19th century.