1968] 
Hermann and Blum — Camponotus 
223 
DISCUSSION 
Based on this investigation and descriptions of the poison apparatus 
of other formicine species, we can describe an apparatus that may 
be considered typical for the subfamily Formicinae. Without excep- 
tion, the poison apparatus of formicine ants, including previously 
investigated species and several other species in our investigations not 
discussed here, ( 1 ) is basically similar in appearance to that of 
stinging species, although (2) the gonapophyses that form the 2nd 
valvulae (sting bulb and shaft) are wanting; (3) there is no valve 
on the lancets; (4) the tongue-and-groove articulations between 
lancets and sting shaft have been lost; (5) the fulcral arms are 
wanting; and (6) the gonostyli have been reduced to membranous 
structures. 
This apparatus of C. pennsylvanicus is typical of formicines in 
other respects. The poison sac in all formicines investigated was 
large and possessed a convoluted structure on much of its dorsal 
surface. The free filaments extend from the base of the sac at the 
proximal end of the convoluted gland. Whether the poison sac is 
similar in all formicine species will have to be investigated, although 
this form holds true for at least two species of Lasius and a species 
of Acanthomyops as well as several species of Camponotus and 
Formica. 
Dufour’s gland in C. pennsylvanicus is typical for species in the 
genera Camponotus and Formica that we have examined, but not 
for some of the more primitive genera. In some species of Lasius 
and Acanthomyops , Dufour’s gland is distinctly unilobular. 
The presence of a large series of free amino acids in the venom 
of C. pennsylvanicus demonstrates for the first time, that formicine 
venoms share some common chemical characteristics with those of 
stinging ants. The majority of these amino acids are found in the 
poison gland secretion of the myrmicine Tetramorium guirteense 
(F.) (Blum and Ross 1965), and free amino acids are also charac- 
teristic of other myrmicine venoms (Blum 1966). Thus, although 
the venoms of no non-formicine ants are known to contain formic 
acid, the assumption that the venoms of formicine species share no 
common chemical components with those of stinging ants is no 
longer tenable. 
The venom of C. pennsylvanicus may be typical of formicines in 
being fortified with free amino acids. We have examined also the 
venom of Formica pallidefulva Latreille and detected the presence of 
free amino acids. It is not improbable that the water-soluble residue 
