XIII 



PHYLUM CHORDATA 



283 



diminishing, owing to the continual flow of blood towards the 

 capillaries. Very soon, therefore, the blood forces the valves 



55 2.S oo ~ 2 ^ ^= 3 2.2'^ = -^ i 

 5 j<! .. " tn ? r- = Si c -2 . . -• -J = ■" < a. 



. .- --§i ^^ 



"22 ic=^ SO > a ic?-- s AH 3 '^■sj^ 



3 



- S ^ -^J .. , s S .> = - ' • " 



■' X ^ r^ 



; itsi 



c S c > ^- -S ic-- = ; " a 3 



s s'^i ;;-2 = b-^ --5.5 . ..-ns 3.2? 



aside and makes its way into the bulbus aortse. Here again the 

 course taken is that of least resistance : owing to the presence of the 

 carotid labyrinth the passage of blood into the carotid trunks is 

 less free than into the wide, elastic, systemic trunks. These will 



