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Show 908 MR. H. H. BRINDLEY ON THE REGENERATION [Nov. 30, (c) Evidence from amputation experiments. In describing these it will be convenient to employ abbreviations, viz:- B and L for right and left. 1, 2, and 3 to denote the respective pairs of legs. t1% t2, and so on for the tarsal joints, starting with the proximal joint. Altogether the legs of 833 immature individuals of S. orientalis of various ages were mutilated and the animals confined in cages till ecdysis occurred. The mutilations were easily performed under chloroform, but it was found that recovery did not occur unless fresh air was admitted immediately the Cockroaches fell on their backs and ceased to struggle. Of the total number operated on 103 were mutilated in one leg and 730 in two legs. In the tabular summary of these experiments given below, " reproduction " must be taken to imply that regrowth of the parts removed took place, and that the new tarsi were always in a/bur-jointed condition. TABLE E. Nature of mutilation. t2 torn away from tL .... tx divided with scissors, -j i Tarsus torn away from | Tibia divided with seis- J Femur torn away from J trochanter 1 Leg mutilated. 3R 2L 3L Total 2R 3R Total 3R 3L Total IL 2R 3L Total Total Number of mutilations. 300 21 109 130 300 89 389 14 300 314 300 17 23 340 1473 Number of reproductions observed. 141 3 16 19 144 45 189 2 122 124 137 4 11 152 625 It will thus be seen that about T 5^ of the mutilations were followed by reproduction of the lost parts accompanied by the appearance of a four-jointed tarsus. The normal five-jointed condition never occurred iu reproduction. In only two or three |