into vessels, whence it proceeds from the^ills to the heart. Tin- 

 circulation is, consequently, semi-vascular and Bemi-lacunar. 



/ i a ,t 



Fig. 45. Circulatory Apparatus in the Lobster.* 



112. Insects. In insects the blood is no longer con- 

 tained in any particular system of vessels ; there are neither 





Fig. 46. Circulation in Insects.t 



* a, the heart : b, the ophthalmic artery ; c, the antennar artery ; </, the 



hepatie artery: r, superior abdominal art- 1 artery; //}/, venous 



sinuses, rcccis iin; the lilmxl eoiniii^ from various jiarts of the IK ><1 v. and trans- 

 niittiiif; it lo the respiratory apparatus (the branchiae h), from whence it 

 returns to the lieart )>y tlie hraneiiio-ear.: 



t The arrows point out the ilireetion of the ( -nrrents : <;, dorsal vessel, in 

 which the blood moves from behind forwards; b, principal lateral currents. 





