Congenital Anomalies of the Heart 1 1 



adherence of the two layers and that true congenital absence was 

 of rare occurrence. 



Two cases in this group deserve special mention, and, as far 

 as I am aware, are unique; in one, by Tait (1868) the pleural 

 cavity was intact while the heart, naked of parietal layer, was 

 in the normal position between the two pleural sacs ; the other 

 case, by Turner (1870), showed the parietal pericardium normally 

 developed except that it was not attached to the diaphragm. The 

 latter condition has been observed as normal for the walrus. 



The condition of defective pericardial development is not read- 

 ily diagnosed and seems to be without clinical interest ; the causes 

 of death ^re entirely independent of the condition and the aver- 

 age age is over forty years. Twice as many males as females are 

 affected. Cases studied are by : 



de Mortel (1700), Baillie (1791), Walter (1805), Otto (1824), Breschet 

 (1826), Meniere (1826), Wolf (1827), Curling (1839), Baly (1852), Bris- 

 towe (1855), Peacock (1866), Powell (1869), Tait (1868), Weisbach 

 (1868), Turner (1870), Bjorsstrom (1871), Lebec (1874), Faber (1878), 

 Chiari (1880), Hughes (1883), Boxall (1887), Hewson (1895), Bernard 

 (1898), Gay (1899), Schendewolf (1900), Primrose (1901), Saxer (1902), 

 Keith (1906) 2 cases, Perna (1909), Verse (1909), Ebstein (1910), Plaut 

 (1913) 2 cases, Cameron (1914), McGarry (1914). Total 36 cases. 



2. Diverticula of the Pericardium. — This condition is of little 

 clinical importance but should be remembered in considering 

 mediastinal tumors. Out pocketings of the parietal pericardium 

 occur, sometimes as cysts, and may reach considerable size. The 

 etiology has not been fully worked out but is probably an arrest 

 of development of some of the layers of the pericardial wall. 

 The condition is rarely encountered and is well illustrated by the 

 following : 



Speir (1865), Cufifer (1875), Bandy (1879), Coen (1885), Atyas-Maraty 

 (1895). Five cases. 



§ V. 



B. MISPLACEMENTS OF THE HEART 



The heart may be found in the neck or as low as the abdomen ; 

 it may be simply misplaced in the thorax (dextrocardia) or it 

 may protrude through a fissure in the ventral body wall (ectopia). 



