62 
Psyche 
[March 
minor regains its feet it is facing in the opposite direction. No major 
of rohweri was ever seen to behave in this way. 
The foraging activities of rohweri are of interest since there is 
evidence that it deliberately forages on the ground. This is probably 
true of texanus as well but it has not yet been conclusively proved in 
that species. On one occasion Dr. F. G. Werner took six foraging 
workers of rohweri from white cholla in the Saguaro National 
Monument. Unless the ants were living in the cactus, which seems 
completely unlikely, they must have reached it over the surface of the 
soil. It is not clear why the foragers had visited the cholla. It was 
not in bloom and efforts by both writers to interest the captive colonies 
in cholla were unsuccessful. Workers in the aquarium colonies spent 
much time crawling over leaves and twigs of various plants with 
which they were kept supplied. When a worker fell from a leaf its 
righting reaction was completely different from that of texanus. 
When a worker of rohweri lands on its back it shows no fixed right- 
ing reaction. The body is violently contorted and the legs are flailed 
about until one of them anchors on something that enables the ant to 
pull itself over. The stereotyped righting reaction of texanus has 
been described elsewhere (4). 
The junior author’s colony was fed on diluted honey, which was 
supplied through a wick from a reservoir. They were also fed on the 
juices of phalaenid caterpillars. It was necessary to tear the cater- 
pillars open before the workers would feed on them. Entire insects, 
either alive or dead, were avoided, as was pollen taken from honey 
bees. The colonies of the senior author were fed on pollen from the 
start. It was found that rohweri will accept a wide variety of pollen 
if it is smeared on the surface of leaves, although they seldom take it 
from the anthers of flowers. Of the various sorts of pollen fed to the 
colonies that of Ouercus agrifolia was clearly the most relished. As 
will be shown, the colonies were also fed with aphid honey dew. As a 
rule they preferred this to pollen but on one occasion, while the ants 
were feeding on honey dew, catkins of Quercus agrifolia were placed 
in the aquaria. The response to these was immediate and spectacular. 
The foragers feeding on honey dew deserted it for the oak catkins 
and practically every worker turned out to take pollen from them. 
They gathered such quantities of pollen that they returned to the nest 
with masses of grains in their jaws. These masses were held against 
the heads of the larvae who nibbled away the pollen grains. The 
original experiments with honey dew were disappointing. The ants 
paid little attention to coccids on the leaves of Quercus chrysolepis or 
to the rims of liquid which surrounded them. They were definitely 
