56 



H. VON W. SCHULTE 



cardia and septum transversum. The dorso-ventral increase 

 in diameter is also marked (fig. 12). 



Upon this condition follows so rapidly the development of 

 the cardiac loop that in only one embryo of 14 somites was an 



fig. 6 Myocardium of a cat embryo of fourteen pairs of somites. Columbia 

 Collection, No. 188. X 300. Reduced one-half, ventral view. L Interven- 

 tricular sulcus; 2, shoulder of left mantle; 3, left bulbo-ventricular sulcus; 4, 

 right bulbo-ventricular sulcus; 5, lateral mesocardia. 



intermediate stage observed. The model of this myocardium 

 is shown in figures 6 to 8. In figure 6 in which the reconstruc- 

 tion is viewed from in front it presents resemblances to Mall's^ 



' Mall, F. P. On the development of the human heart. Am. Jour. Anat., 

 vol. 13, 1912, fig. 1. Cf. Dandy, W. E. A human embryo with seven pairs of 

 somites, measuring about 2 mm. in length. Id., vol. 10, 1910. Also Evans, 

 Keibel and Mall. Manual human embryology, vol. 2, figs. 408-9, and Mall, Ibid., 

 vol. 1, figs. 382-G. 



