Template:Congdon1922 table1

Embryo No.	Length in mm	Arches present	Characteristic features
1878	1.3	1	slightly plexiform. Presomite stage
1201	2	1
391	2	1	7 somites
470	4	1	neuropore open; 14 to 16 somites
2053	3	1, 2 beginning	Anterior neuropore closed; 20 somites; transverse anastomoses between primitive aortae
1201b	3	1, 2
836	4	2, 3	Earlier mandibular artery ; paired longitudinal neural arteries; no ventral tract on cord
Just before establishment of fourth arch; estimated average length 4 mm; 31st day of development
826	5	3, 4	Earlier mandibular and hyoid arteries
1075	6	3, 4	Subclavian
588	4	3, 4	Earlier mandibular and hyoid arteries
873	6	3, 4	Ventral tract on cord
988	6	3, 4
1380	4	3, 4; pulmonary arches almost complete
2841	4	3, 4; 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	3, 4, and pulmonary arches	Late stage in formation of basilar artery; Splitting of aortic sac distinct. Unpaired aorta complete
1354	6	3, 4, and pulmonary arches
617	7	3, 4, two so-called fifth arches, and pulmonary arches	Subclavian artery surrounded by brachial plexus. Splitting of sac well marked
792	8	3, 4, and pulmonary arches	Pulmonary and 4th arches widely separated below
1121	11	3, 4, and pulmonary arches	Right pulmonary artery small; basilar rounded; 4th and pulmonary still further apart
721	9	3, 4, and pulmonary arches	Cervical segmental arteries becoming interrupted
163	9	3, 4, and pulmonary arches	Anastomoses of cervical segmental arteries to form the vertebral artery are nearly complete
Time of interruption of pulmonary arch and branchial period; estimated average length 12 mm; 45th day of development
1771	13	3, 4, left pulmonary and remnant of right pulmonary arch
544	10
940	14
1909	15
492	16
74	16
End of period of rapid descent of heart and arteries; estimated average length 18 mm; 50th day of development
1390
460
2937
886
Estimates based on Keibel F. and Mall FP. Manual of Human Embryology II. (1912) J. B. Lippincott Company, Philadelphia. curve of length and age.
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.

Congdon (1922) Table 1

Embryo No. Length in mm Arches present Characteristic features 1878 1.3 1 slightly plexiform. Presomite stage 1201 2 1 391 2 1 7 somites 470 4 1 neuropore open; 14 to 16 somites 2053 3 1, 2 beginning Anterior neuropore closed; 20 somites; transverse anastomoses between primitive aortae 1201b 3 1, 2 836 4 2, 3 Earlier mandibular artery ; paired longitudinal neural arteries; no ventral tract on cord   Just before establishment of fourth arch; estimated average length 4 mm; 31st day of development 826 5 3, 4 Earlier mandibular and hyoid arteries 1075 6 3, 4 Subclavian 588 4 3, 4 Earlier mandibular and hyoid arteries 873 6 3, 4 Ventral tract on cord 988 6 3, 4 1380 4 3, 4; pulmonary arches almost complete 2841 4 3, 4; 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 3, 4, and pulmonary arches Late stage in formation of basilar artery; Splitting of aortic sac distinct. Unpaired aorta complete 1354 6 3, 4, and pulmonary arches 617 7 3, 4, two so-called fifth arches, and pulmonary arches Subclavian artery surrounded by brachial plexus. Splitting of sac well marked 792 8 3, 4, and pulmonary arches Pulmonary and 4th arches widely separated below 1121 11 3, 4, and pulmonary arches Right pulmonary artery small; basilar rounded; 4th and pulmonary still further apart 721 9 3, 4, and pulmonary arches Cervical segmental arteries becoming interrupted 163 9 3, 4, and pulmonary arches Anastomoses of cervical segmental arteries to form the vertebral artery are nearly complete   Time of interruption of pulmonary arch and branchial period; estimated average length 12 mm; 45th day of development 1771 13 3, 4, left pulmonary and remnant of right pulmonary arch 544 10 940 14 1909 15 492 16 74 16   End of period of rapid descent of heart and arteries; estimated average length 18 mm; 50th day of development 1390 460 2937 886   Estimates based on Keibel F. and Mall FP. Manual of Human Embryology II. (1912) J. B. Lippincott Company, Philadelphia. curve of length and age. 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.