THE ANIMAL BODY 



137 



SPINAL CORD 



NEURAL CANAL 



NOTOCHORD 



COELOM 



BRAIN 



ORAL CAVITY/ 



GILL SLITS HEART 



-CLOACA 



SPLEEN URINARY BLADDER 



BILE DUCT 

 PANCREAS 



Fw. 74. Diagrammatic longitudinal section of an ideal Vertebrate (female). 

 (From Hegner, after Wiedersheim.) 



sp.c 



FIG. 75. Diagrammatic transverse section through the trunk of an ideal 

 Vertebrate, en, centrum of vertebra; coel, coelom; crd. v, cardinal vein; d.ao, 

 dorsal aorta; d.f, dorsal fin; d.m, dorsal muscles; f.r, fin-ray; gon, gonad; int, 

 intestine; l.v, lateral vein; mes, mesentery; ms.n.d, mesonephric duct; ms.nph, 

 mesonephros; na, neural arch; p.n.d, pronephric duct; pr, peritoneum, parietal 

 layer; pr', peritoneum, visceral layer; r, subperitoneal rib; r', intermuscular rib; 

 sp.c, spinal cord; t.p, transverse process; v.m, ventral muscles. (From Parker 

 and Haswell.) 



