to mean that in a homogeneous assemblage of families there is no correlation between the grade of booting of parents and offspring. CHAPTER VII. NOSTRIL-FORM. In my 1906 report I described in detail the form of the nostril in poultry. Usually it is closed down to a narrow slit, but in some races, as, _e. g._, the Polish and Houdans, the closing flap of skin fails to develop and the nostril remains wide open. This is apparently an embryonic condition. Thus in Keibel and Abraham's (1900) Normaltafeln of the fowl it is stated that the outer nasal opening, which is at first wide open, becomes closed with epithelium at about the middle of the sixth day of development. The Polish and Houdan fowl thus retain in the outer nasal opening an embryonic condition. The question is: How does this embryonic, open condition of the nostril behave in heredity with reference to the more advanced narrow-slit condition? The wide-nostriled races used were both the Polish and the Houdan. The condition of the external nares is much the same in the two, but is slightly more exaggerated in the Houdans than in the Polish. The open nostril is often associated with a fold across the culmen, apparently due to the upturning of the anterior end of the premaxillary process of the nasal bone. Breeders of Houdans have sought to exaggerate the height of the fold. In both races there is great variability in the degree of "openness" of the nostril, and to indicate this I have adopted a scale of 10 grades (running from 1, the narrowest, to 10, the widest). To get some idea of this variability let us consider the grade of nostril in some families of pure Houdans. TABLE 45.--_Variability (expressed in decimal grades) of the degree of "openness" of the nostrils in families of "pure-bred" Houdans._