Daltonism, the commonest form of color-blindness in which the affected individual is unable to discriminate between red and green.
Dendrites (Gr. dendron, tree), branching processes which spring from nerve-cells.
Determiner (L. determinare, to determine), the distinctive cause or unit in a germ-cell which determines the development of a particular character in the individual derived from that cell. The terms gene and factor are sometimes used as synonyms of determiner.
Dihybrids (L. di, two; hybrida, mongrel), the offspring of parents differing in two characters.
Diploid (Gr. diploos, double; eidos, form), the dual or somatic number of chromosomes.
Dominant Character (L. dominare, to be a master), a character from one parent which manifests itself in offspring to the exclusion of a contrasted character from the other parent.
Drosophila, a genus of fruit-flies of which there are several species.
Duplex (L. duo, two; plico, fold), the condition in which a character is represented by two determiners, one from each parent.
Electrotropism (Gr. electron, amber; tropē, turning), defined, [p. 198].