232 
Psyche 
[June-Septernber 
not seen, were estimated to be respectively 29, 36 and 1 1, with 95 per 
cent confidence intervals of (25, 33) (25, 47) and (5, 19). 
Comments on Table 1: 
Some behavioral categories deserve special mention: 
1 . Carry pupa or lick pupa: Care of pupae consisted exclusively of assisting eclosion 
to adult. The pupae remained in the brood chamber and only when the colony was 
disturbed (which did not happen during the drawing of the catalog) media workers 
carried them to the new nest. 
2. Lay trophic egg: The actual laying of trophic eggs was not seen, but 3 times 
media workers were seen offering the larvae and the queen small, round, shiny 
objects, looking like eggs, but different from the normal ones laid by the nest queen. 
It is not impossible that the laying of trophic eggs is a real but rare event. 
3. Recruitment behavior: In order to determine whether the workers utilize any 
kind of food recruitment, the colony was deprived of food for one week and the nest 
connected to an arena by a bridge of round sticks. Honey water was presented on the 
arena floor. Two periods of one hour observation were recorded. Initially all ants 
that reached the food source were collected and not allowed to return by the bridge. 
Between the two experiments the honey source, the bridge and the arena floor were 
changed to avoid recognition by the ants. In the first period 35 ants reached the food 
source, in the second 262. This experiment clearly shows that this species uses food 
recruitment. Returning ants were observed to rub the tips of the abdomen on the 
bridge sticks (probably laying a scent trail) and to display no nestmates. During the 
construction of the catalog, however, no recruitment behavior was noted, probably 
because the colony was kept fed to saturation. 
4. Jittering and antennal tipping: These behavioral categories were described by 
Wilson (1976), but nothing is known about their meaning. 
5. Defensive behavior: Our perpilosa colony was not stressed to ellicit defensive 
behavior. However, a stray individual of the ant Novomessor cockerelli was found on 
the nest floor being attacked by media and minor workers of Formica perpilosa: not 
even in this situation the majors were observed outside the nest. This of course does 
not mean that majors cannot play a role in defending the nest against predators or 
raids by other ants, but it is apparent defense is not their characteristic behavior. A 
more detailed account of the defensive behavior of this species should be useful. 
After the behavioral catalog was drawn, 50 specimens had their 
head widths and lengths measured and plotted. The linear ana- 
morphosis afforded a linear regression of head length on head 
width, where the coefficient of determination is r 2 = .964. When 
logarithmically plotted, in order to compare with Wilson’s model 
