llegeneratioH of Tarsus li'c. in Orthoptera saltutorii. 237 



XX X I. — Regeneration of the Tarsus and of the Two Anterior 

 J'dirs of Limbs in the Orthoptera sahatoria. By Kdmdn'u 

 lidKDACK *. 



1. — It wouM be useless to trv ami jirovoke self-mutihition of 

 tin- first two pairs ot" limhs in the Orthoptera saltatoria. By 

 ^iviiij^, however, a strong pull to the legs, they may be sepa- 

 rated from the body. Such separation rarely takes place at 

 the joint between the femur and trochanter f, but much more 

 «>ften at that between the latter and the coxa. The injury 

 thus inflicted upon the insect is generally fatal ; the muscles 

 break irregtdarly, making a ragged tiit't, while bleeding is 

 copious. When the Orthoptoron survives, if it still be in 

 the larval state, regeneration can act and produce either a 

 perfect limb when separation has taken place at the joint 

 between femur and trochanter, or a more or less rudimentary 

 stump when the trochanter has been severed from the coxa. 



These facts seem in a twofold manner to invalidate the law 

 of Lessona : — l»tly, because there is regeneration at points 

 where mutilations do not appear to be normally produced; 

 2iidly, because regenerations at the two places are most 

 frequent in the one where pulling more rarely leads to the 

 separation of the limb, and because they are without any 

 com[)arison more comj)lete in the same region. 



If we notice what lia|)pens during the changes of skin, we 

 shall see that this double paradox breaks down before an 

 examination of the normal facts. 



In point of fact, it is by no means rare during moulting for 

 one of the limbs to be detached from the body by exuvial 

 self -mutilation. Contrary to what we found before, separation 

 takes place almost always at the joint between the femur and 

 the trochanter, and very rarely at that between the latter and 

 the coxa. In the first of these cases bleeding is compara- 

 tively insignificant, while in the second it may be fatal. 

 Mutilation in such a way is much less severe and less fre- 

 quently followed by deith than if it had been produced 

 experimentally. The power of regeneration often acts in the 

 first case, and may sometimes produce a perfect linib|. When 



♦ Translated from ' Comptes Rendus,' cxxix. (July 17, 18'JU) pp. 169- 

 171, by Wilfred Mark Webb, F.L.S. From a separate impression 

 couiiminicated by the Autlii>r. 



t It is impossible sometimes even to separate it at this point by pulling, 

 lu Gri/lli/.t camjHstrig, for instjince, I have to make use of scissors to effect 

 the removal. 



X .Vraong the Orthoptera saltatoria the parts in process of regeneration 

 ffrow slowly, from which the experimenter may be at first tempted to 

 believe that such regeneration does not exist. Also a reproduced limb 



