DYTISCUS (Gr. dytes, a diver), a Linnwan genus of aquatic coleopterous insects or water-beetles, now forming the tribe or family dytiscidce. They are pentamerous coleop tera; that is, have all the tarsi five-jointed. Their general form is oval, the outline little broken, and the surface very smooth. The respiratory organs of the perfect insect are not adapted to the extraction of air from water, and it must occasionally come to the surface to breathe, where it rests fora short time back downward,-and.with the extrem ity of the abdomen eiposed to the air, the opbnings ofothe air-tubes cbeing in the last segment. The dytisei do are excessively voracious, feeding upon any kind of animal food, and boldly attacking creatures larger than themselves. They are very amusing inmates of the fresh-water aquarium, and sometimes live in it for a year or two, getting tame, and readily coming to be fed with small earth-worms, bits of beef, etc. The spe cies are numerous, and vary much in size, some being very small, and some almost 2 in. in length. A very common British species is D. marginalis, about an inch and a quarter in length, of a dark olive color, the thorax and outer sides of the elytra margined with yellow. All the species are found in lakes, ditches, marshes, and the still parts of rivers. They often leave the water by night, and can fly well. Their larvae have the body long and tapering, composed of eleven rings or segments, besides the head. They hide themselves in the earth, in chambers which they make for them selves, before changing into pupae.
DY'VEld (L e., dove), called by the Latin chroniclers Columbula, the mistress of
Christian II. of Denmark, has been often celebrated in works of poetry and fiction. She was born in Amsterdam in 1488, and Christian became acquainted with her in 1507, in Bergen, where her mother, Sigbrit 1Vylms, had settled as an innkeeper. She followed him to Opslow, and, when he mounted the throne, to Copenhagen. Notwithstanding the marriage of Christian with Isabella, the sister of the emperor Charles V., his rela tion with D. was continued, and her mother acquired unbounded influence in the affairs of the country. Though D. herself never interfered, she was naturally hated by the party of the nobles; and her death, which happened suddenly in 1516, was attributed, with almost certainty, to poison. The poison was understood to have been administered to her in cherries by the noble and proud relations of the governor of the palace, Torben Oxe, who was a suitor for the affections of Dyveke. On her death, the character of Christian broke out in all its savageness. He first ordered the treasurer Faaburg to be executed for having said that Torben Oxe had enjoyed the favor of D.; and then at the instigation, as was given out, of a nightly vision, Torben Oxe himself. Sams5e, a Dan ish poet, wrote, about the end of the 18th c., a tragedy called Dyveke, often represented in Copenhagen. The story has since been made the subject of several novels and trag edies; e. g., Zabern, by J. C. Hauch, a Dane; and Riekhoff's tragedy, Daveke (Berl. 1843).