Dis´tichous, a. Two-rowed; spread apart on either side of a middle line, as the hairs of a squirrel’s tail, or the tail-feathers of the Archæopteryx.
Ditok´ous, a. Producing but two eggs, as the pigeon and humming-bird.
Diur´nal, a. Pertaining to the daytime.
Divar´icate, a. Branching off; spreading apart; curving away.
Divertic´ulum, n. An offshoot of the small intestine.
Dor´sad, a. Toward the back. Opposite of ventrad.
Dor´sal, a. Pertaining to the back.
Dor´sum, n. Back; upper surface of trunk from neck to rump. (57.)
Down, n. Small soft feathers of plumulaceous structure, generally growing about the roots of plumæ, and concealed by them. See Plumulæ.
Down´y, a. Of plumulaceous structure. A part of the plumage is of down-feathers, and the bases of the contour feathers usually also are of downy structure.