14 C. W. M. Poynter 
they will be indicated by a communication between normally dif- 
ferentiated arteries, Hektoen (1905). 
Not all cases of a single trunk from the heart belong to this 
class of irregularities. The cases of Farre (1814) and Foster 
(1846), Vierordt thinks, are cases of atresia of the aorta; atresia 
of the pulmonary artery will be discussed on page 14. Since 
these cases seem to represent arrest of development of the aortico- 
pulmonary septum and are in a measure independent of the 
accompanying cardiac defects I have classed them together. 
The following represent all of the degrees of the anomaly in- 
cluded in section I, A: 
Wilson (1798), Standert (1805), Lawrence (1814), Meckel (1816), 
Tiedemann (1825), Breschet (1826), Martin (1826), Mayer (1827), Blum- 
hardt (1834), Crisp (1847), Dubrueil (1847), Clark & Owen (1848), Toyn- 
bee (1849), Hale (1850), Chevers (1851), Deutsch (1851), Hyernaux 
(1851), Pozzi (Chevers 1851), Vernon (1856), Bernard (1860), Wilks 
(1860), Turner (1862), Fraentzel (1868), Hickman (1869), Messenger 
(1873), Rokitansky (1875), Baginsky (1879), Crocker (1879), two cases, 
Caesar (1880), Peacock & Reed (1880), Rickards (1881), Grant (1883), 
Berrand, Barry & Rachet (1884), Brewer (1885), Brocq (1885), Clarke 
(1885), Barbillon (1886), Ziegenspeck (1888), Muhr (1889), Pryor (1889), 
d’Renzi (1889), Klipstein (1890), Charrin & Le Noir (1891), Girard 
(1895), Gallois (1896), Cade (1897), Cazin (1897), Petschel (1897), Ci- 
vatti (1900), Orlowski (1902), Gutkind (1903), Lefas (1904), Rispal & 
Bay (1904), Keith (1909), Wenner (1909), Dickson & Fraser (1914). 
B. Atresia of the Pulmonary Artery Usually Accompanied by 
Perforate Septum Ventriculare or Patent Ductus Arteriosus 
Perhaps no form of cardio-vascular defect is more familiar to 
the general student than pulmonary stenosis, on account of its 
comparative frequency and marked clinical manifestations. It 
has been exhaustively studied by Kussmaul (1865), Rauchfuss 
(1878) and Vierordt (1898), consequently I will not review the 
large literature but will confine this classification to the cases in 
which the pulmonary artery is not functional. 
In the cases of atresia of the pulmonary artery, as in other 
anomalies, different degrees of the defective development are to 
be found; 7. e., all of the variations from a normal artery with ob- 
242 
