Evolution.

  • Society for Experimental Biology (Great Britain)
Date:
1953
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Evolution. Source: Wellcome Collection.

    378/484 (page 346)
    348 LOCOMOTORY HABITS AND THE EVOLUTION Increase of speed in Peripatus is accomplished largely by a decrease in the relative duration of the backward stroke and by an increase in the angle bottom gear PERIPATUS top gear PAUROPUS CRYPTOPS A SPIROSTPvEPTUS POLYDESMUS FORFICULA ЛАЛ лЛ/^ BUTHUS ASTACUS SPIDER LIGIA Fig. 5. Single segments of a series of Arthropoda are shown in transverse section, with their limbs drawn relative to the ground as seen in the living animals. The scales chosen are those which in each case give a segment of the same volume, and the two figures of Peripatus represent the same segment employing different gaits. The sco^ion and spider show walking legs 3, Astacus and Forficula walking leg 2, and Ligia walking leg 6. of swing of the leg. In the Arthropoda vera both these factors substantially contribute to their speed increases. In the Scolopendromorpha alone the