On either side of the body between the mantle and the foot are two flat gills each composed of two lamellae. _Cardium_ belongs to the order of Lamellibranchia in which the gills present the maximum of complexity, the original vertical filaments of which they are composed being united by interfilamentar and interlamellar junctions. In other respects the anatomy of the cockle presents no important differences from that of a typical Lamellibranch. The sexes are distinct, and the generative opening is on the side of the body above the edge of the inner lamella of the inner gill. The eggs are minute, and pass out into the sea-water through the dorsal or exhalent siphon. The breeding season is April, May and June. The larva for a time swims freely in the sea-water, having a circlet of cilia round the body in front of the mouth, forming the velum. The shell is developed on the dorsal surface behind the velum, the foot on the opposite or ventral surface behind the mouth. After a few days, when the mantle bearing the shell valves has developed so much as to enclose the whole body, the young cockle sinks to the bottom and commences to follow the habits of the adult. The usual size of the cockle in its shell is from 1 to 2 in. in breadth.
The common cockle is regularly used as food by the poorer classes. It occurs in abundance on sandy shores in all estuaries. At the mouth of the Thames the gathering of cockles forms a considerable industry, especially at Leigh. On the coast of Lancashire also the fishery, if it may be so called, is of considerable importance. The cockles are gathered by the simple process of raking them from the sand, and they are usually boiled and extracted from their shells before being sent to market. The cockle is liable to the same suspicion as the oyster of conveying the contamination of typhoid fever where the shores are polluted, but as it is boiled before being eaten it is probably less dangerous. (J. T. C.)
COCKNEY, a colloquial name applied to Londoners generally, but more properly confined to those born in London, or more strictly still to those born within the sound of the bells of St Mary-le-Bow church. The origin of the word has been the subject of many guesses, from that in John Minsheu's lexicon, _Ductor in linguas_ (1617), which gives the tale of the town-bred child who, on hearing a horse neigh, asked whether a "cock neighed" too, to the confusion of the word with the name of the Utopia, the land of Cockaigne (q.v.). The historical examination of the various uses of "Cockney," by Sir James Murray (see _Academy_, 10th of May 1890, and the _New English Dictionary_, s.v.) clearly shows the true derivation. The earliest form of the word is _cokenay_ or _cokeney_, i.e. the _ey_ or egg, and _coken_, genitive plural of "cock," "cocks' eggs" being the name given to the small and malformed eggs sometimes laid by young hens, known in German as _Hahneneier_. An early quotation, in Langland's _Piers Plowman_, A. vii. 272, gives the combination of "cokeneyes" and bacon to make a "collop," or dish of eggs and bacon. The word then applied to a child overlong nursed by its mother, hence to a simpleton or milksop. Thus in Chaucer, _Reeve's Tale_, the word is used with _daf_, i.e. a fool. The particular application of the name as a term of contempt given by country folk to town-bred people, with their dandified airs and ignorance of country ways and country objects, is easy. Thus Robert Whittington or Whitinton (_fl._ 1520), speaks of the "cokneys" in such "great cytees as London, York, Perusy" (Perugia), showing the general use of the word. It was not till the beginning of the 17th century that "cockney" appears to be confined to the inhabitants of London.