 his saying and for this reason what also enters the essence of the brain means and since the thin membrane is like the placenta in preserving or losing the veins from which the brain is nourished it is necessary that this membrane have a large entrance into the essence of the brain in order to deliver nourishment to it from those veins.
قوله ولذلك ما يداخل أيضا جوهر الدماغ معناه ولما كان الغشاء الرقيق كالمشيمة في حفظ أو ضاع العروق التي منها يغتذي الدماغ وجب أن يكون لهذا الغشاء مداخلة كبيرة لجوهر الدماغ ليوصل إليه الغذاء من تلك العروق.