Diagram of the Circulation of an Insect.
Insects have neither arteries nor veins. The circulation, such as it is, is animated by the action of a vessel called dorsal, which is situated above the digestive tube. Labels: 1, Dorsal vessels in which the blood flows. 2,The lateral currents. The arrows show the outward and the inward current.
Cutter, Calvin First Book on Analytic Anatomy, Physiology and Hygiene, Human and Comparative (Philadelphia: J. B. Lippincott & Co., 1875) 127