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Show 912 MR. H. II. BRINDLEY ON THE REGENERATION [Nov. 30, of the above-mentioned authors and those of Durieu l, Fredericq ', Beyerimhoff3, and Werner4 may be referred to. More recently, however, Griffini5, quoting the above in connection with cases he has observed of apparent reproduction of appendages in Gomphocerus, Oedlpoda, and Prlstes, concludes that, as is the case in the Cursoria, reproduction may not improbably occur during the post-embryonic development of the Saltatoria also. From these statements it appears that more extended observations would show that among the Orthoptera alone the more immediate effects of injury to a limb differ considerably in the several tribes of the order. While in some genera a slight stimulus may bring about immediate autotomy at a certain fixed place, in others little or no autotomy is observable even when strong means of stimulation, such as amputation of the more distal portions of a limb, are employed, the injury in such cases being followed sometimes by the eventual dropping away of certain portions of the remaining stump, and sometimes by the retention of the entire stump. Again, though the subject of autotomy necessarily bears a close relation to that of reproduction of lost parts, there seems to be no direct ratio between the degree of autotomy exhibited and the power of reproduction possessed in any particular case. More or less parallel are the diverse results obtained from mutilation of the limbs in different genera of Arachnida recorded by Heineken6, Blackwall \ Barize8, and Fredericqs, to whose work fuller reference will be made later on in connection with the phenomena of reproduction of the lost parts. Mortality In confinement.-About 25 °/0 °I the 833 mutilated individuals died before accomplishing an ecdysis. Apparently this mortality was not due to the injuries inflicted, for it was not excessive in the period immediately following mutilation, but occurred at a steady rate throughout the experiment. The animals were kept in three glass-fronted boxes 24 x 8 X 10 inches in size, and provided with narrow dark shelters imitating the crevices haunted by Cockroaches when at large. The boxes remained throughout tbe experiment in a room kept at a temperature of 16° C. It is very possible that these arrangements reproduced the natural habitats too imperfectly and that overcrowding, or want 1 " Notes sur quelques Orthopteres," Petites Nouv. Entomol. 1876, no. 158. 2 Loc. cit.; also 'La Luttepour l'existence chez lesAnimaux Marins' (Paris, 1889), p. 259. 3 " Note sur l'atrophie des membres chez les Orthopteres," Miscellanea Entomologica, 1896, iv. p. 70. 4 " Selbstverstummelung bei Heuscbrecken," Zool. Anzeiger, 1892, Jahrg. xv. p. 58. 5 "Di un Pristes tuberosus anomalo," Boll, de Musei di Zool. ed Anat. Comp. Torino, 1896, xi. no. 234 ; also "Di due Acrididi anomali," ibid. xi. no. 256. c Loc. cit. 7 "Report on some recent Researches into the Structure, Functions, and Economy of the Araneidea made in Great Britain," Brit. Assoc. Rep. 1845, p. 62. 8 " L'amputation reflexe des pattes des Crustacea," Rev. Scientifique, 1886, ser. 3, xi. p. 379. " Loc. cit. |