Template:Congdon1922 table1

Table 1. Showing correlation of size of embryos and development of the aortic-arch system.
Embryo No.	Length in mm.	Arches present.	Characteristic features.
Time of establishment of first arch; estimated average length 1.3 mm.; 23d day of development
1878	1.3	I	Slightly plexiform. Presomite stage
1201	2	I
391	2	I	7 somites
470	4	I	Neuropores open; 14 to 16 somites
2053	3	I; II beginning	Anterior neuropore closed; 20 somites; transverse anastomoses between primitive aortae
Template:CE1201b	3	I. II	Earlier mandibular aitery; paired longitudinal neural arteries;
836	4	II, III	no ventral tract on cord
Just before establishment of fourth arch; estimated average length 4 mm.; 31st day of development
826	5	III, IV	Earlier mandibular and hyoid arteries
1075	6	III, IV	Subclavian
588	4	III, IV	Earlier mandibular and hyoid arteries
873	6	III, IV	Ventral arterial tract on cord
988	6	III, IV
1380	4	III, IV, pulmonary arches almost complete
2841	4	III, IV; one so-called fifth arch; pulmonary almost complete	Early formation of basilar artery
Just before completion of pulmonary arch; estimated average length 6 mm.; 36th day of development
810	5	III, IV, and pulmonary arches	Late stage in formation of basilar artery, Splitting of aortic sac distinct. Unpaired aorta complete
1354	6	III, IV, and pulmonaiy arches
617	7	III, IV, two so-called fifth arches, and pulmonary arches	Subclavian artery surrounded by brachial plexus. Splitting of sac well marked. Islands at end of basilar artery
792	8	III, IV, and pulmonary arches	Pulmonary and IV arches widely separated below
1121	11	III, IV, and pulmonary arches	Right pulmonary artery small; basilar rounded; IV and pulmonary still farther apart
721	9	III, IV, and pulmonary arches	Cervical segmental arteries becoming interrupted
163	9	III, IV, and pulmonary arches	Anastomoses of cervical segmental arteries to form the vertebral artery are nearly complete
Time of interruption of pulmonary arch and of branchial period; estimated average length 12 mm 45th day of development
1771	13	III, IV, left pulmonary and remnant of right pulmonary arch
544	10		Vertebral artery complete; identity of arches disappearing; beginning of period of rapid descent of heart and arteries
940	14		Definitive aortic arch just taking form. Right dorsal aorta between III and IV interrupted. Remnants still distinguishable. Main pulmonary channel from heart to aorta nearly straight
1909	15		Common carotid elongated
492	16		Right dorsal aorta distal to IV patent but slender
Template:CE74	16		End of period of descent. Definitive aortic arch has curve of large radius. Short segment of right dorsal aorta distal to subclavian drawn out in slender thread
End of period of rapid descent of heart and arteries; estimated average length 18 mm.; 50th day of development
1390	18		Definitive aortic arch sharply bent
460	20		Summit of definitive aortic arch at superior thoracic aperture
2937	24		Sternal bands in contact through most of their length
886	43		Origin of right and left pulmonaiy" branches in contact through most of their length
Age estimates based on Keibel F. and Mall FP. Manual of Human Embryology II. (1912) J. B. Lippincott Company, Philadelphia. curve of length and age.    Table as image   Table Reference: Congdon ED. Transformation of the aortic-arch system during the development of the human embryo. (1922) Contrib. Embryol., Carnegie Inst. Wash. Publ 277, 14:47-110.