Two rates of carbon dioxide flow into the termination chamber were applied for the euthanasia of rats. The classical phases of asphyxia were observed in both groups of animals although their course was prolonged in rats exposed to the lower gas flow. The haemorrhages were assessed histologically in the following structures: the pericranium, compact bone and diploë of the skull, sagittal suture, nape muscle and its attachment, and the dura. The haemorrhages appeared regularly in the sagittal suture in all cases from both experimental groups. The possible significance of this phenomenon for the forensic practice was pointed out.