172 ELEMENTS OF MAMMALIAN ANATOMY 



DEVELOPMENT OF THE HEART 



The development of the heart in the eat has been carefully 

 worked out for the earher stages by Schulte ('16) and in the 



Fig. 86a. — Cat Embryo ok Nine Somites. (Modified after Schulte, Am. Jour. 



Anal., Vol. 20, p. 51.) 

 a, lateral hearts; b, digestive tract; c, nervous system. 



Fig. 86&. — Cat Embryo of Twelve Somites. {Modified after Schulte.) 

 a, lateral hearts about to fuse; h, endothelial layer; c, myocardium. 



pig by Miss Sabin ('17). According to Schulte the heart 

 develops by an approximation, fusing and looping of certain 

 lateral primordia lying in the dorsal wall of the open intestine 



