72 Psyche [June 
The small amount of venom available did not permit any further 
chemical characterizations. 
The venom secreted from the sting of this ant is derived primarily, 
if not exclusively, from the true poison glands. Examinations of the 
poison glands of numerous ants from which venom had been collected 
frequently revealed that the poison vesicles were collapsed, whereas 
in every case Dufour’s gland was distended with liquid. This was 
also the situation with glands from ants which had been allowed to 
sting human subjects. Although it is possible that traces of the 
secretion from Dufour’s gland are secreted with the venom from the 
poison glands, it is quite evident that the biologically active secretion 
issuing from the sting; of this ant essentially possesses the character- 
istics of the contents of the true poison glands. 
Skin Responses of Hu?nans to the Sting 
Prior to stinging, the worker grips the skin with its mandibles and 
then arches the thorax upward so that the abdomen is bent under- 
neath. The thorax and abdomen often form a sharply inverted v with 
a narrow angle between. This characteristic pose is a reflection of 
the elongate structure of these ants and probably provides the ant 
with sufficient leverage to drive the lancets into the skin. Although 
workers may sting for 30 seconds or more, multiple stings at one 
site were not frequently obtained. 
Figure 2 . The lancet of Pseudomyrmex pallidus. A, triangular plate (first 
valvifer) ; B, ventral apodeme of triangular plate; C, ramus of lancet (first 
valvula) ; D, valve of lancet; E, ligulate membrane; F, dorsal fin of lancet; 
G, main body of lancet; H, tip of lancet. 
