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Show 1897.] OE THE LEGS IN THE BLATTID.E. 911 ecdysis of the remaining parts up to the suture. Scudder does not speak of immediate loss suggesting autotomy as usually understood, but he states that the regrowth which replaced the lost parts necessarily always commenced from the above place. On the other hand, Bordage * describes well-marked autotomy and subsequent reproduction in two other genera of Fhasmids as always occurring at the femoro-trochanteric suture. As in the case of the Blattidae, these observations on the Fhasmidae were on individuals which had not performed their final ecdysis, after which reproduction of lost appendages ceases. Bordage, who employed different kinds of stimuli for bringing about autotomy, found that the age of the individual, as well as the mode of stimulation, was a controlling factor in the readiness with which autotomy occurred. Heineken 2, early in this century, experimented on the autotomy of the posterior, or jumping, legs iu genera of Gryllidae, Locustidae, and Acridiidae ; while more recently Fredericq 3 and Contejean 4 have observed in detail the autotomy of the jumping-legs of Locusta viridlsslma. The experiments of these authors show that the autotomy of the jumping-legs takes place at the femoro-trochanteric suture. [The statement of the last-named that inasmuch as the trochanter is absent in Locusta viridlsslma, the autotomous break occurs between femur and coxa, appears to rest on the fact that in this species the trochanter is telescoped into the coxa in such a manner as to be visible only when the femur is removed. In a spirit-specimen a sharp pull on the femur always leaves the trochanter still attached to the coxa. In connection wdth this point, as well as with others in the present enquiry, I am indebted to Dr. David Sharp, F.B.S., for much kind advice and assistance.] The above-mentioned authors, in addition to ascertaining that different methods of injury and stimulation caused autotomy after a shorter or longer latent period, demonstrated that the event is dependent on the integrity of the third pair of thoracic ganglia, and is as truly a reflex action as the autotomy exhibited by the appendages of Decapod Crustacea, or the tail in certain Lizards. In connection with these observations it must be noted that the power of reproducing lost legs is usually supposed to be absent in the Orthoptera Saltatoria. Graber5 has observed reproduction of the antennae in Grgllus and Locusta, but could not obtain reproduction of the tarsi. For further information the writings 1 " Phenomenes d'autotomie observes chez les nymphes de Monandroptera in-uncans et de Khaphiderus scabrosus," Comptes-Rendus Acad. Sci. 1897, cxxiv. pp. 210 & 378. 2 Loc. cit. p. 427. 3 " Les mutilations spontanees ou l'autotomie," Rev. Scientifique, 1886, ser. 3, * "Sur l'autotomie chez la Sauterelle et le Lezard," Compt.-Rend. Acad. Sci. 1890 cxi. p. 611. 3 ''Zur Entwickelungsgeschichte und Reproductionsfahigheit der Ortho-pteren," Sitzungsb. der Akad. cl. Wiss.,Math.-naturw. CI. lv. Bd. i., Wien, 1867; also Ann. & Mag. Nat. Hist. ser. 3, xix. p. 147. |