Arterial Anomalies 21 
ically normal, Crocker (1879) ; they are represented in figs. 22 
and 23. 
The two remaining combinations are generally known as trans- 
position of the aorta and pulmonary artery; they may be de- 
scribed as follows: 
t. A failure of rotation of the aortico-pulmonary septum in a 
heart in which the ventricular loop has rotated normally. The 
aorta is situated in front of the pulmonary artery and opens 
from a tricuspid ventricle. This is the most frequent form of 
transposition, fig. 20. 
2. A failure of rotation of the aortico-pulmonary septum in 
a heart in which the ventricular loop has rotated in the reverse di- 
rection. The aorta is situated in front of the pulmonary artery 
and opens from a tricuspid ventricle. The condition is the mir- 
ror picture of “1” and might be found in a case of situs viscerum 
transversus. For explanation see fig. 21. 
3. A group of cases which do not fall in either “1” or “2” 
have been encountered. The aorta is in front of the pulmonary 
artery and opens from a bicuspid ventricle. The condition is 
very unusual and I know of no theory to account for the anomaly 
which does not present great difficulties. I have offered the 
theory of Lochte, which Wenner (1909) thinks is satisfactory, 
as presenting the most logical explanation; see fig. 24. 
The following illustrative cases are arranged according to the 
classification just given for transposition: 
Transposition, Class A: Langstaff (1811), Baillie (1812), Farre (1814), 
Lawrence (1814), Meckel (1816), Otto (1816), Wolf (Ref. Kreysig 1817), 
Kreysig (1817), Nasse (1821), Miller (1822), d’Alton (1824), Burkart 
(1825), Tiedemann (1825), Breschet (1826), Bock (Ref. Cerutti 1827), 
Holst (1836), Martin (1839), Ducrest (1840), Ewen (1840), Friedberg 
(1844), King (1844), Beck (1846), Parker (1847), Jackson (1849), Parker 
(1849), Johnson (1851), Ward (1851), Keil (1854), Peacock (1855), Meyer 
(1857), Reynolds (1857), Hervieux (1861), Cockle (1863), Libert (1863), 
Meigs (1867), Arnold (1868), Frankel (1870), Kelly (1871), Pye-Smith 
(1872), Ogston (1874), Barlow (1876), Maier (1876), Elliot €1877), Jane- 
way (1877), Martin (1877), Babesiu (1879), Chiari (1879), Mackenzi 
(1879), Mazzotti (1879), Lees (1880), Ashby (1881), Kleinschmidt (188r),. 
Peacock (1881), Talini (1881), Bianchi (1882), v. Etlinger (1882), Holl 
(1882), Peacock (1882), Pope (1882), Scott (1882), Crocker (1883), 
249 
