To examine the regenerative ability of different claw segments, single claw digits (dactyl or pollex), both claw digits (dactyl and pollex), or proximal segments of the claw (ischium + merus/carpus joint) were autotransplanted into eye sockets.
To determine whether walking legs can regenerate from eye sockets, tissues from the dactyl, ischium, and the merus/carpus joint of the fourth walking legs were contralaterally autotransplanted into eye sockets.
Thus, the coxa and ischium are proximal segments of the claw; the dactyl and pollex are the distal "digits" of a claw.
Table I Summary of limb tissue autotransplantation in the eye socket of Cancer gracilis (carapace width = 12.05 [+ or -] 3.40 mm) (*) Type of regenerate Trials Survival Donor tissue Host eye (No.) (No.) Limblike Limb Claw dactyl ipsi 15 6 0 0 dactyl contra 17 8 1 0 pollex ipsi 15 8 2 0 pollex contra 10 3 1 0 dactyl + pollex ipsi 19 13 2 2 dactyl + pollex contra 23 15 1 1 frozen dactyl + pollex ipsi 12 9 0 0 dactyl + pollex + ischium contra 20 15 1 3 ischium + joint ipsi 23 14 1 1 ischium + joint contra 13 10 1 2 Walking leg dactyl + ischium + joint contra 19 12 3 1 Sham operation ipsi 25 18 0 0 Total 211 131 13 10 * Limblike: a structure that resembles a claw or walking leg and in which handedness cannot be recognized; limb: a claw or walking leg in which handedness can be recognized.