INTRODUCTION. XEXV 
appears then to be separated from the rest 
by a little whitish band, which is nothing 
more than this membrane. The abdo- 
men is composed of four or five rings, 
the last of which gives passage to the 
‘sexual organs and the sting. 
Latreille regards the scale as charac- 
teristic, which rests on the fillet of the 
abdomen, and takes the place of a 
ring, which, without that, would be 
wanting in the abdomen of these insects. 
These are his words:—¥** Naturalists,”’ he 
says, ** have not considered that this 
scale or these knots on the peduncle of 
the abdomen of ants are only the first 
rings shaped in this way. Several wasps 
have also the first segment of the abdo- 
men formed likea knot. To decide this 
point, let us count the number of rings 
of which the abdomen of ants is com- 
posed ; we know, and it is a constant rule 
with respect to insects of this order, that 
there are seven rings in the abdomen of 
males, and six in that of females. Let 
us see if, after taking away the scale and 
a 6 
