34 
Psyche 
[March 
Figure 2. Sagittal section through the tergal gland complex, showing the chan- 
nels that open through the intersegmental membrane. 
ants were fixed in alcoholic Bouin (Dubosq Brasil), embedded in 
Methyl Methacrylate and sectioned 8 m with a Jung Tetrander I 
microtome (Rathmayer 1962). The staining was Azan (Heiden- 
hain). The SEM pictures were taken with an AMR 1000 A Scanning 
Electron Microscope. For comparative morphological studies of 
cuticular surface structures we used dry specimens of the ant col- 
lection of the Museum of Comparative Zoology of Harvard Uni- 
versity. 
Results 
Whenever we dug up a nest of N. albisetosus we noticed a very 
repugnant odor. The same odor can be released when the gaster 
of a Novomessor worker is crushed. First we assumed that the 
substance originates either from the poison gland or the Dufour’s 
gland or the hindgut, yet after all these organs were removed from 
the gaster the abdominal residue still exuded the odor strongly. 
Next we dissected segment by segment. In this way we finally de- 
termined that the odor was emanating from the third and fourth 
