A series of 40 chicken embryos were processed after 19 d of incubation by dissection, diaphanisation, skeleton stained with alizarin red and examined by image analysis. Six bones (femur, tibiotarsus, tarsometatarsus, humerus, ulna and carpometacarpus) and 4 parameters (perimeter, area, the largest and the smallest Feret diameter) were evaluated. The smallest Feret diameter proved unusable. The coefficients of variation for the other 3 parameters were comparable for the 6 bones. All the bones were valuable for comparing morphometric values between a control population and a population treated with a xenobiotic in order to quantify the chemical's influence on ossification.