320 NOTES AND COMMENTS [November 
Regeneration in Orthoptera. 
Mr. Edmund Bordage, of Réunion, although recently laid aside by 
fever, continues to send home notes in regard to regeneration in Phas- 
midae, Mantidae, Blattidae, and other Orthoptera. Their theoretical 
interest is so great that we venture to refer at some length to two or 
three recent papers by this observer. 
In twenty-five species of Orthoptera with five-jointed tarsus, re- 
presenting twenty-one genera and three families, the regenerated tarsus 
has only four joints. The number given in his published paper is 
eighteen species, but a manuscript note on the copy sent us states it 
at twenty-five. 
In Phylloptera laurifolia and Conocephalus differens (Locustidae), 
Acridium rubellum (Acrididae), and Gryllus campestris (Gryllidae), 
there is no trace of regenerative capacity in connection with the 
posterior legs, which are used in jumping. ‘This appears at first sight 
an argument against the generality of Lessona’s law, since these hind 
lees are surely much exposed to the bites of enemies, besides being 
liable to injury in the moults. Bordage’s answer is that the loss of 
these limbs makes moulting extremely difficult, exposes the insects to 
great danger at the hands of their enemies, prevents copulation, and 
places the unfortunates at a great disadvantage in preferential mating. 
He concludes that jumping Orthoptera which have lost their hindmost 
legs are unable to propagate, and that this explains the absence of 
regenerative capacity in this particular case. 
In another paper (Comptes Rendus Acad. Scr. Paris, exxix. 1899, 
pp. 169-171), Bordage points out that it is impossible to provoke 
autotomy of the first two pairs of legs in saltatorial Orthoptera. By 
main force a separation may be effected at the articulation of trochanter 
and coxa, or rarely at the articulation of femur and trochanter. The 
mutilation is often fatal, but if the insect survives and is still larval, 
regeneration may be effected, perfectly if the separation was between 
femur and trochanter, more or less rudimentarily if between trochanter 
and coxa. 
This raises a double difficulty for those who uphold Lessona’s law : 
—(1) the regeneration seems to occur at points where mutilation 
cannot be naturally effected ; and (2) the regeneration is most frequent 
and most complete when the separation has been effected along the 
line where rupture is rarest. 
Bordage gets over the difficulty by pointing out that in the 
“exuvial autotomy,” ie. self-mutilation during a moult, the separation 
is most frequent along the femur-trochanter articulation, and very rare 
along the trochanter-coxa articulation. The bleeding is insignificant 
in the first case, but it may be fatal in the second. Moreover, re- 
generation in the first case is frequent, and, though slow, sometimes 
