50 
INTERNAL STRUCTURE, 
afford attachment to many mmscles, therefore it has 
to be very much strengthened. To give it more 
extensive support the top of 
each pillar is forked (Fig. 24, 
h). It is these pillars which 
make the bee’s head so strong, 
though its external skeleton is 
thin. Macloskie found that 
these pillars ascend in front 
of the central brain-lobes, run- 
ning between them and the oph- 
thalmic lobes, and keep the large ocular apparatus in 
its place. 
Then, close to the bases of these pillars, rods (Fig. 
23, rise and run forward towards the front of the 
head. They are firmly fixed, widen out at the root, 
and are slightly pliant, their motion being limited by 
a web which binds them to the base of the head. 
These rods are forked at the ends and support the 
lor a (Kirby, 76) (Fig. 23, ^), jointed by a very per- 
fect elbow joint, and which also gives support to the 
maxillae. The position of these rods is shown in 
transverse section at <r. Fig. 24. 
The thorax, as the source of locomotion, has a 
very great strain upon it, and to prevent it collapsing 
we find the difficulty overcome by corrugations and 
plaitings of the external skeleton, besides strong webs 
to give it great rigidity. There is also a stiff plate called 
tHe mesophragma (Fig. 21, h) which lies between the 
meso- and meta-thorax, and gives attachment to some 
of the powerful muscles which move the wings. 
Diagram of Transverse 
Section Head of Bee. 
