In addition to the above brooches or fibulæ (group 1)--all developments of the safety-pin type--there are three other large groups of brooches: (2) the circular disc type; (3) the penannular or Celtic brooch; and (4) the ring-brooch. The first of these--the type generally worn at the present day--may be described as a flat disc fitted with a hinged pin. In cemeteries belonging to the Early Iron Age in Southern Europe circular plates have been found fitted with a pin. These plates appear[1] to have been developed by the conversion of a primitive disc of spiral concentric wire into a circular plate. From the brooch of this type sprang the circular brooch of the Roman period, often inlaid with enamel, as well as the splendid circular brooches of Anglo-Saxon times, and all other disc-shaped brooches. In all early periods, and even in Roman times, the bow or safety-pin type of brooch was commoner than the disc and also more practical, as it offered room for the gathered folds of the garment. In modern times the disc-shaped brooch fitted with a hinged or sometimes with a spring pin has been principally used. [1] Ridgeway (W.), _Early Age of Greece_, p. 437. [Illustration: Celtic brooch.] [Illustration: Ring-brooch (Tomb of Queen Berengaria of Navarre, wife of Richard Coeur de Lion, at Le Mans).] The two remaining groups of brooches--(3) the Celtic brooch and (4) the ring-brooch--are both developments of the simple pin in combination with a ring--in the former case penannular and in the latter annular. The Celtic brooch, with penannular ring and long pin, is apparently the result of fitting a pin to a prehistoric form of fastening for the dress--a penannular ring terminating with knobs, known as a mammillary fibula. The ring-brooch with complete ring, and pin of the same length as the diameter of the ring, which was popular in mediæval times, is the outcome of fitting a complete ring of wire to a pin to prevent the head of the pin from slipping through the material--which ring in course of time became the more important member. It is improbable that the Celtic brooch originated in the same way, from the union of a long pin with a small ring. Nor is it likely that these two forms of brooches were evolved the one out of the other by the shortening or lengthening of the pins. As a matter of fact the two appear to have arisen independently side by side.