1897.] OF 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 Phasraids as always occurring 

 at the femoro-trochanteric suture. As in the case of the Blattidse, 

 these observations on the Phasmidse 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 ^, early in this century, 

 experimented on the autotomy of the posterior, or jumping, legs in 

 genera of Gryllidse, Locustidte, and Acridiidse ; while more recently 

 Fredericq ^ and Oontejean ■" have observed in detail the autotomy of 

 the jumping-legs of Lociista viridissima. 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 viridissima, 

 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 con- 

 nection -ndth this point, as well as with others in the present 

 enquiry, I am indebted to Dr. David Sharp, F.R.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. Graber ' has observed reproduction 

 of the antennae in Gryllus and Locusta, but could not obtain 

 reproduction of the tarsi. Eor further information the writings 



1 " Phenomenes d'autotomie observes chez les nytnphes de Monandroptera in- 

 uncaiis at de Rhaphiderus scahrosus," Comptes-E«ndus Acad. Sci. 1897, cxxiv. 

 pp. 210 & 378. 



2 Loc. cit. p. 427. 



5 " Les mutilations spontanees ou I'autotomie," Kev. Scientifique, 1886, ser. 3, 

 xii. p. 613. 



* "Sur I'autotomie chez la SaiitereUe et le Lezard," Compt.-Eend. Acad. Sci. 

 1890, cxi. p. 611. 



° "Zur Entwickelungsgeschiehte und Reproductionsfahiglieit der Ortho- 

 pteren," Sitzungsb. der Aiad. d. Wiss., Math.-naturw. 01. Iv. Ed. i., Wien, 1867 ; 

 also Ann. & Mag. Nat. Hist. ser. 3, xix. p. 147. 



