Cross-section of Phormia larva showing the aorta (ao),its lumen (1)and the surrounding pericardial cells(pn).Note the net-like fat body. AORTA OF PHORMIA ADULT TRACHEA AORTA INTERSEGMENTAL MUSCLES o/wwlacutync的u-nserts/page9t如hingresaurces1 ASOIRCI生ATORY9STE1过道