536 General Notes. (May, 
the Thysanura and Collembola. He finds, according to the Jour- 
nal of the Royal Microscopical Society, that the wing-muscles 
appear to have developed along two lines; in one, the indirect 
flying muscles were almost completely aborted, while in the other 
they were developed at the expense of the direct muscles. In 
close connection with the development and modification of these 
muscles is the extent of concentration of the rings of the thorax 
and the size of the wings. In the Orthoptera all the three seg- 
ments of the thorax are freely movable on one another, while in 
the Coleoptera only the prothorax is so movable. In the Lep 
doptera the prothorax loses its mobility, though retaining its dis- 
tinctness, while in the Diptera and Hymenoptera the whole region 
is converted into a firm thoracic apparatus, to which, in the latter, 
the first abdominal segment also becomes applied. As Graber 
has shown, we observe that in insects which by other points @ 
their organization intimate that they are more highly developed, 
one pair of wings tends to become aborted, as is seen in = 
Coleoptera, Diptera, and even Lepidoptera, where the hin 
pair of wings often become united with and share in the move 
ment of the anterior pair. 
RESPIRATORY CENTER oF Insects. — According to a 
the respiratory center in the bee is situated in the anterior Ang 
and therefore the respiratory movements are put an en ‘nds 
decapitation. Dr. O, Langendorff, from his investigatii 
that in the bee, wasp, and other insects, the faer ha 
ments are not destroyed by removal of the head, especially cided, 
by tearing, and not cutting it off, a great loss of blood "4 av pidity 
e respiratory movements show the same increase eM e 
with a high temperature, slowing with a low temperatur: 
headless insect as in the uninjured insect. Libellula de- 
number of experiments were also made upon E in 
ressa and other insects belonging to the Pseudont ae 
which group the segmentation of the body is very mar ax e respir® 
spondence with their ancestral type; in these inserta i oe 
tory center is not merely not localized in the hen respiratory 
segment is a complete center in itself, being capable o e to illus- 
movement, when entirely isolated. “A better gera hardly 
be imagined; each segment with its ganglion 1s a P aon are 
unity!” The results of a great number of obser i 
fully stated in the paper, and several diagrams are lt Roy. 
ings obtained of the respiratory movements.— JOu 
Society, February, the flat- 
MOUTH-PARTS or THE Hemrprera.—O. Geise r pi the Ry* 
` tened or more or less curved process of the clypeus- th ointed 
chota as the homologue of the labrum of bena he 
trat- 
ej 
sete tot 
groove corresponds to the labium, the two separable 
