38 C. W. M. Poynter 
(1822), Godman (1824), Wagner (1828), Green (1830) 2 cases, Lauth 
(1830), Dubrueil (1837) 2 cases, Demeaux (1841), Brent (1844), Quain 
(1844) 5 cases, Tiedemann (1846) 4 cases, Pigné (1847), Cavasse (1856), 
Barkow (1866), Wood (1867), Barkow (1869) 3 cases, Bankart, Pye- 
Smith, Phillips (1869) 2 cases, Pye-Smith, Howse, Davies Colley (1871), 
Carrier (1880), Giacomini (1882) 2 cases, McArdle (1885), Brodie (1888), 
Shepherd (1890), Thomson (1891), Abbott (1892), Leboucq (1894), 
Jacques (1895), Gotz (1896), Herrick (1897), Holzapfel (1899) 4 cases, 
Banchi (1907), Warren Museum 5 cases. 
For the detailed classification of the cases in this list see the following 
sections) ILL B, 2c. Mil Ga’ TIliG26- TID) td elle) Taso mlelem ae 
ayia OG 10), se (DS IU, 1). Abe WU WL A Ge 100l, 1D > a, 
2. The right aortic arch is present and is represented in the 
proximal portion of the right vertebral artery, which seems to 
spring from the right common carotid. In this group conditions 
are the same as in group I, except that the right vertebral springs 
from the right common carotid instead of. from the right sub- 
clavian artery. Reference to fig. 13 will explain the method of 
development of the irregularity. The theory of its occurrence was 
first suggested by Brenner (1883) and was based on the relation 
of the right recurrent laryngeal nerve. This has the same rela- 
tion to the vertebral artery in these cases as it bears normally to 
the subclavian artery of this side. It will be seen that this theory 
necessitates considering that the vertebral has an origin in a 
higher segmental artery than the subclavian, but, as is pointed out 
in considering the development of the vertebral, page 10, this is 
not unreasonable. It would seem that the disturbing develop- 
mental factors have affected just the connection between the 
sixth and seventh segmental arteries and the right dorsal aortic 
root; or perhaps the primary defect was in the connection be- 
tween the segmental arteries, and the resulting anomalies, 7. e.. 
persistence of the sixth segmental artery and the right dorsal aorta, 
are in the nature of compensation for this irregularity of develop- 
ment, see fig. 39. 
The following cases belong to this group: 
Murray (1768), Green (1839), Simon (1846), Tiedemann (1846), Du- 
brueil (1847), Hyrtl (1859), Wood (1859), Brodie (1888), Shepherd 
(1890), Abbott (1892), Solger (1893), Suzuki (1894), Holzapfel (1899), 
Kemmetmiller (1911) 3 cases, Hasebe (1912). 
266 
