482 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
the question of the origin and relations of the different components of 
the sting. He finds that the twelfth body segment develops in the 
same way as do the other segments ; but while in these the parts become 
tergum, sternum, &c., in the metamorphosed twelfth segment they be- 
come parts of the stinging apparatus. Thus the epipygium represents 
the tergum, the oblong plates, with their connecting membrane, the 
sternum. The Terebrantia retain the primitive condition in that these 
parts fuse into a complete ring similar to the other body rings, while in 
the Aculeata the separate parts are withdrawn into the abdomen. 
Further careful examination of the abdominal segments shows that 
their anterior (presegmental) and posterior (postsegmental) surfaces 
display secondary thickenings and outgrowths. Homologous structures 
occur in relation to the eleventh and twelfth segments and form parts 
of the sting. The homologies of these parts are considered in detail. 
As to the morphology of the gonapophyses in the narrow sense (darts, 
sheath, and groove), the author does not believe that these can be 
homologised with abdominal appendages, but regards them as new 
formations having no relation to appendages. Their rudiments are 
post-embryonic, appearing much later in development than the rudi- 
ments of the true abdominal appendages, which appear and disappear in 
the embryonic stage. 
Regeneration in the Mantidae.* — M. Edmond Bordage finds that in 
this family, as in the other pentamerous Orthoptera, regenerated limbs 
have four joints in the tarsus in place of the normal five. As, including 
the present observations, tetrameric regeneration has been observed in 
eighteen pentamerous Orthoptera distributed in the three families, the 
author concludes that it occurs in the whole group. It also seems to 
follow from the author’s observations that as a rule the tetramerous 
regeneration of the tarsus in Orthoptera pentamera after self-mutilation 
has its seat in the trochantero-femoral groove. 
Wings of Insects.f — Messrs. J. H. Comstock and J. G. Needham 
conclude their discussion of the specialisation of wings by addition with 
an account of the tracheation of the wings of Orthoptera. In this and 
preceding instalments they furnish data for determining the homologies 
of the veins in each of the orders of winged insects except the Euplexo- 
ptera, Mecaptera, Isoptera, and Physopoda. From this phase of the 
subject they propose to pass to a study of the beginning of wings. 
Histology of Digestive Tube in the Larva of Chironomus.J — P. 
Vignon strongly opposes the vesicular theory of the secretion of glandu- 
lar cells. He believes that the vesicles described by many authors are 
due to injury to the cells produced during fixation ; they are never visible 
in living intact animals. He finds further that the peritrophic membrane 
has no relation to the coats of the chylific stomach, but arises from the 
mid-gut above the proventriculus. In some specimens cilia are distinctly 
demonstrable in the three regions of the chylific stomach, and also in the 
terminal part of the intestine where the chitin is very thin. 
* Comptes Eendus, cxxviii. (1899) pp. 1593-6; Trans, in Ann. and Mag. Nat. 
Hist., iv. (1899) pp. 115-8. 
t Amer. Nat., xxxiii. (1899) pp. 573-82 (8 figs.). Cf. this Journal, ante, p. 155. 
X Comptes Kendus, cxxviii. (1899) pp. 1596-8. 
