12 THE THORAX. 
The thorax is generally considered to consist, as in 
other insects, of three divisions —the prothorax, meso- 
thorax, and metathorax. I have elsewhere, however, 
given reasons into which I will not at this moment 
enter, for considering that the first abdominal segmeni 
has in this group coalesced with the thorax. The 
thorax bears three pairs of legs, consisting of a coxa, 
trochanter, femur, tibia and tarsus, the latter composed 
of five segments and terminating in a pair of strong 
claws. 
In the males and females the meso- and meta- 
thorax each bear a pair of wings, which, however, are 
stripped off by the insects themselves soon after the 
marriage flight. 
The workers never possess wings, nor do they show 
even a rudimentary representative of these organs. 
Dr. Dewitz has pointed out that the full-grown larve 
of the workers possess well-developed ‘ imaginal disks,’ 
like those which, in the males and females, develope 
into the wings. These disks, during the pupal life, 
gradually become atrophied, until in the perfect insects 
they are represented only by two strongly chitinised 
points lying under the large middle thoracic stigmas. 
No one unacquainted with the original history of 
these points would ever suspect them to be the rudi- 
mentary remnants of ancestral wings.! 
The thorax also bears three pairs of spiracles, or 
breathing holes. 
' Zeit. f. wiss. Zool., vol. xxviii. p. 655 
