160 
ME TAMORPHOSIS. 
The embryonic larva has seventeen ganglia (Fig. 
58, a), one supra-oesophageal (or cervical), three small 
sub-oesophageal (i/), which later fuse into one, as seen 
at c, three thoracic (r), and ten abdominal (^^), of 
which, according to 
Brandt ( 10 ), three 
unite and form the 
last but one abdominal 
ganglion in the larva, 
which then has only 
eight abdominal gan- 
glia. When the chry- 
salis stage is reached 
the second and third 
thoracic and the first 
and second abdominal 
ganglia coalesce into 
a single nerve mass 
{d, c). Other ganglia 
also coalesce, so that 
in the adult stage, c, 
the worker has five ab- 
Fig. 58. — Diagram showing Ganglia 
in various Stages of Development. 
dominal ganglia, and the drone and queen only four 
(Brandt). 
Fig. 58 is a diagram showing the different stages, //, 
representing the head, r, thorax, and Ab abdomen. 
The brackets in diagram b show the various ganglia 
that coalesce : c represents the ganglia in the adult 
stage of a worker. 
Girard ( 48 ) says that embryogeny shows the 
digestive tube of insects to be formed in three parts — 
