MODIFICATIONS OF THE AORTIC ARCHES. 



91 



Fig, 25. 



, Mn. Hy Br.l Br.^ Bn^ Bt:^ Br.^ Bi:^ Br.' 



II 1 Jl I I I _ I _l _ I I 



A. 



@ 



I nmivvvivnvmix: 



10 fefefeffefeP 



rAV. 



■AC. 



AD. 



A.C. 



AD. 



AC. 



I II Mivv\T:viiYiirK 



Fig. 25. — A diagram intended to show the manner in which the aortic 

 arches become modified in the series of the Vertebrata. 



A. A hypotheticallj' perfect series of aortic arches, corresponding with 

 the nine postoral visceral arches, of which evidence is to be found in 

 some Sharlis and Marsipobraiickii. A.C. Cardiac aorta ; A.D. Dorsal 



