114 
Psyche 
[June 
Figure 2. Two walking patterns of females orienting up-wind towards the “call- 
ing” male, redrawn in sequence of 1 / 18 sec from cine film. The small dots represent 
the position of the female’s head, the tails indicate the body axes. The wind was a 
light breeze of unknown speed, the direction was approximately determined with 
cigarette smoke. 
is assumed to be steep, direct osmochemotactic orientation is pos- 
tulated without the need of air movement. An experimentally 
proved analysis of the postulated mechanisms has not been firmly 
worked out so far, and neither can the answer be given for the case 
of Hodotermes sex attraction. This species, however, appears to 
be an ideal subject for experimental analysis because of the insist- 
ent motivational impetus in the performance of postflight behavior 
except for the difficulty in catching the swarming time. 
The Sternal Gland 
The sternal gland in termites is known as the source of the trail 
pheromone (Stuart, 1969 and 1976; Bruinsma et al., in prep.). The 
involvement of the gland in sexual attraction during the imagines’ 
