Maternal height and twinning.

Data on maternal height are presented for 307 pairs of newborn twins of known zygosity from Oxford and 267 pairs from Aberdeen and north-east Scotland. The results support the hypothesis that mothers of DZ twins are taller than those of MZ twins. Mothers of MZ twins resemble mothers of singletons in height, whereas mothers of DZ twins are taller.

The effect of zygosity on the birth weight of twins in Aberdeen and northeast Scotland.

Birth weight data for 356 pairs of newborn twins of known zygosity and placentation are presented. The combined weights of dizygotic twins are heavier than those of monozygotic twins. The significance of this finding is discussed in relation to the association between increased maternal height and dizygotic twinning.

Probable common origin of a hereditary fundus dystrophy (Sorsby's familial pseudoinflammatory macular dystrophy) in an English and Australian family.

A genealogical link was established six generations back between a family living in England and Australia, and one of the families reported originally by Sorsby et al (1949) as suffering from autosomal dominant inflammatory macular dystrophy (fundus dystrophy). The onset--in the fifth decade of life--and the progress of the condition, which usually ends in blindness, has been observed in a number of patients and the prodromal development of a colour vision deficiency in some of them confirmed. This defect is fundamentally different from the X-linked colour vision defects and merits further investigation.

Correlated odour threshold bimodality of two out of three synthetic musks.

The odour threshold bimodality for exaltolide described by Whissell-Buechy & Amoore (1973) among American whites is confirmed for a population sample in London. A highly correlated bimodality presumed to be caused by the absence of inactivity of certain receptor sites is shown to exist for another structurally different musk substance, musk ambrette. The thresholds for musk ketone show no bimodality and their correlation with the thresholds for the two other musks is low.