Since the well-known work by Hamburger and Hamilton ( 195 1) on normal chick enlbyros appeared, a number of workers have “? staged― embryos of various species of birds. They clearly established morphological and structural characteris tics as more reliable criteria than chronological age in the staging of chick enibryos. Rempel and Eastlick ( 1957) showed constant differences between embryos of the White Silkie bantam and standard varieties of the domestic chicken. Koeke ( 1958) described the embryonic stages of the domestic duck. Mumi and Kosin ( 1960) correlated the development of broad-breasted bronze turkey eiiibryos with the chick. Although few significant differences were recorded, they showed that the turkey embryo has a distinctive structure, the “? snood― or “? leader,― which serves as an important criterion for older stages. Hanson ( 1954) applied candling and special photographic techniques in determining the age of mallard. wood duck afl(l bob-white quail embryos. His primary purpose was to determine the age of embryos at the nest site. In the present paper, normal stages of chick enhl)ryo development ( Hamburger and Hamilton, 1951 ) were used as the basis for establishing the stages of develop ment for the quail. It is known that the quail embryo takes approximately 23 days to hatch, as compared with 21 days in the chick. Thus, the niajor objective of this study was to correlate the developmental stages of quail and chick embryos, and to identify the periods of incubation when the quail embryo “? lags― behind in development. Since all photographs, descriptions and measurements are based on material fixed in FAA (5 ml. formalin, 90 ml. 70% ethyl alcohol, 5 ml. glacial acetic acid), minor distortions may have occurred. Freshly laid fertile eggs were obtained froni the State Ganie Farm, Mount Vernon, Illinois. They were incubated in a Farm Master incubator at a temperature of 99.5 F. dry bulb and about 89.0° F. wet bulb. During the course of this study several hundred embryos were examined from the unincubated stage until hatching. No constant differences were observed between ciuail and chick embryos through stage6 (25 hours) (Hamburger and Hamilton, 1951) and referenceto thesestages will be omitted. Between stages 7 and 14, which are based primarily on the number of pairs of visible somites, the quail embryo lags in development so that l)ystage 14 (22 somites) itis 12—16 hours olderthan the chick. The gradual lag in developmental ratecontinuesso thatb@ stage24 the quailembryo is24 hours behind the chick enibryo iii morphological development. Flexion and rotation of