 he said and the entire brain is divided in its length by a half that penetrates its veils and its marrow and in its ventricles. as for the half of the skull at its top it is apparent. that is because in its interior there is a protrusion that goes in its length under the sagittal suture and this protrusion has a benefit other than the division. what remains is that the bone is thick when it connects to the sagittal suture so that it compensates for what separation causes in terms of weakness of the body.
قوله وجميع الدماغ منصفا في طوله تنصيفا نافذا في حجبه ومخه، وفي بطونه أما بنصف القحف في أعلاه فظاهر. وذلك لأنه في باطنه نتوء ذاهب في طوله تحت الدرز السهمي ولهذا النتوء فائدة غير التنصيف ويبقى أن يكون العظم عند اتصاله بالدرز السهمي غليظا فيكون بذلك متداركا لما يوجبه الانفصال من وهن الجرم.