Congenital Anomalies of the Heart 39 



The causative factors are still in debate ; Peacock discussed the 

 possibilities and came to the conclusion that in the cases where 

 the number of cusps was reduced a large majority were of con- 

 genital origin but that in certain cases a fusion of the leaflets from 

 endocarditis mig'ht occur after birth and be difficult to recognize. 

 Abbott quotes Osier as saying that the cases are due to fusion 

 during fcetal life because: (i) The presence of a low, sometimes 

 half-obliterated raphe behind one of the cusps; (2) compensa- 

 tory changes in the cusps so that their free edge becomes equal 

 to or even shorter than the single segment, and (3) the fusion 

 of the coronary or right and left segments. Launois et Villaret 

 (1905) concluded that the cases they studied were congenital 

 because there was no -histological evidence of inflammation or 

 adhe^on. In the cases of supernumerary leaflets there is gen- 

 erally no question of the congenital origin of the case. A few 

 cases have been found in which a band stretches across the lumen 

 of the artery above the valves; Archer (1878) thinks these are 

 anomalous supernumerary cusps. 



The classification is simple, as indicated by the arrangement of 

 the following cases : 



A. Pulmonary Semilunar Valves. 



1. No valves: Whittle (1889). 



2. One valve: Moore (1892). 



3. Two valves: Graves (1841), Ward & Parker (1846), Jackson (1849), 

 Peacock (1849), Buhl (1857), Peacock (1856), Loschner & Lambl (i860), 

 Peacock (1866) 4 cases (1871), Deguise (1872), Buhl (1878), Pott (1878) 

 2 cases, Mackenzie (1879), Peacock (1879), Borresi (1880), Lees (1880), 

 O'Sullivan (1880), Revilliod (1882), Tooth (1883), Durozier (1885), Vite 

 (1886), Foot (1888), Hebb (1889), Oliver (1889), Preisz (1890) 2 cases, 

 Fennell (1891), Delitzin (1892), Saunders (1892), Rheiner (1896), Hebb 

 (1897), Minkowski (1904), Carpenter (1906), Kiihne (1906), Carpenter 

 (1908), Girauld et Tissier (1910), Wassenbach (1910), Hebb (1913) 2 

 cases, Monteiro (1917). 



4. Four valves: Tuineau-de Mussy 1836), Loschnfer & Lambl (i860), 

 Carter (1873), Wilson (1876), Bernard (1880), Briininghausen (1880), 

 Tirard (1880), Martenotti (1886), Vite (1886), Delitzen (1892) 3 cases, 

 Virchow (1896), Crowder (1897), Griffith (1897), Launois et Villaret 

 (1905), Reid (1911). 



B. Aortic Semilunar Valves. 



I. One valve: Martenotti (i^ 



