Arterial Anomalies 27, 
Scheffer (1903), Schreiber (1903), Letulle (1904), Chartier (1905), Apert 
& Brézard (1906), Ellis (1906), Carpenter (1909), Weiss (1909), Wenner 
(1909), Robertson (1911), Variot & Moranci (1911), Hayashi (1912), 
Keith (1912), Gasquet (1913), Hebb (1913), Matzfeldt (1913), Milland 
(1914). 
The following cases are considered from the diagnostic standpoint 
during life: Burghart (18098), Zinn (1808), Dressler (1902), Pfeifer 
(1902), Starck (1902), Arnheim (1903), Bittorf (1903), Hochsinger 
(1907), Wessler & Barss (1913). 
B. Persistence of Both Fourth Arches 
The persistence of the fourth right embryonal arch in conjunc- 
tion with the left arch produces a peculiar and rare anomaly. 
If there is a maintenance of the early embryonal condition, fig. 5, 
the right, posterior, arch will pass over the right bronchus and 
give origin to the right subclavian and carotid arteries; the left, 
anterior, arch will be in somewhat near the normal position of 
the aortic arch and will give origin to the left carotid and sub- 
clavian arteries. The arches will join dorsally somewhat below 
the attachment of the ductus arteriosus and will thus form a com- 
plete vascular ring about the trachea and cesophagus. 
The following cases may be classified under this head: 
Hommel (1737), Biumi (1765), Malacarne (1784), Bertin (1824), Za- 
gorsky (1824), v. Siebold (1836), Hyrtl (1841), Blandin (1842), Rendu 
(1842), Jones (1846), Cruveilhier (1851), Thomson (1863), Watson 
(1877), Shepherd (1880), McKee (1887), Heller (1904), Hamdi (1906), 
Gladstone & Wakeley (1915). 
The case of Malacarne is somewhat irregular, fig. 26, and diffi- 
cult to explain. The internal and external carotids come from 
the arch and probably represent an absence of the third arches. 
Hommel’s case, fig. 27, seems to represent the typical condition. 
The case reported by Zagorsky consists of an anterior arch which 
is evidently the normal one and which gives origin to the in- 
nominate trunk and the left common carotid. The posterior 
trunk passes between the cesophagus and the trachea, giving off 
the left subclavian before joining the descending aorta. It is dif- 
ficult to understand how, if this right vessel is the right arch, it 
reached the position in front of the cesophagus ; on the other hand 
255 
