412 



ZOOLOGY FOR MEDICAL STUDENTS 



CHAP. 



flap-like structure attached to the heart-wall along its headward edge. 

 From the free edge of the valve and also from its outer surface pass 



Fig. 182. 

 Heart of the Frog. \ General dissection from the ventral side. a.v.D, Dorsal atrio-ventricular 

 valve ; a.v.L, left ditto ; a.v.R, right ditto ; b, bristle passed from ventricle into conus ; C, conns ; 

 c, carotid ; l.a, left auricle ; p.v, opening of pulmonary vein ; pc^ pulmo-cutaneous ; r.a^ right 

 auricle ; s, systemic cavity ; s.a, atrial septum ; sx, septum of conus ; s.o, opening from sinus 

 venosus ; V, ventricle ; v. A, ventral aorta. 



scattered cords of connective tissue to the ventricular wall which serve 

 to limit the movement of the valve. 



