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Fig. 122.—The same by the left fore (l1), middle (l2), and hind, leg (l3) of a Carabus. Natural size.

Fig. 123.-Tracks of a Blaps mortisaga marked by the differently painted tibial points: ●, tracks of fore, —○, middle, —/, hind leg. Natural size.

Fig. 124.—Tracks of Necrophorus vespilio. Natural size.

“To be more exact, it is usually thus: At first (Fig. 118) the left fore leg (L1) steps out, then follows the right middle leg (R2), and the left hind leg (L3). Then while the left fore leg begins to retract and thus make the backward movement, the right fore leg is extended, whereupon the left middle leg and the right hind leg are raised in the same order as the first three feet.”

Graber^[23] painted the feet of beetles and let them run over paper, and goes on to say:

“Let us first pursue the tracks of the Blaps, for example (Fig. 123). Let the insect begin its motion. The left fore leg stands at a, the right middle leg at β, and the left hind leg at c. The corresponding number of the other set of three feet at α, b, γ. At the first step the three feet first mentioned advance to a′β′c′, the second set on the other hand to α′b′γ′. Thereby the tracks made by the successive steps fall quite, or almost quite, on each other, as appear also in the tracks of a burying beetle (Fig. 124).