OVER a period of two months, a heavy rat population on a farm in the west of Scotland was treated with two anticoagulant poisons, ‘Diphacinone’ and ‘Warfarin’. Although the treatments were ...

SINCE 1949, Barr et al. and others 1–3 have described the presence of ‘sex chromatin’ in various tissues of several animal species, arriving at the conclusion that in all of them behaviour ...