1937] 
Habits of Strumigenys 
99 
remains. I cannot believe that the authors imply that such 
fragments pass into the abdominal portion of the digestive 
tract. If the infrabuccal pocket is meant, however, it should 
be recalled that Wheeler and Bailey have clearly shown (3) 
that this structure may be entirely devoid of recognizable 
insect remains in the case of an ant known to be insecti- 
vorous. The absence of such remains is, therefore, no proof 
that insect tissues are not used as food. While I could not 
accept the above conclusion as offered I was anxious to test 
the hypothesis of the two authors that the ants might be 
fungus feeders. This seemed entirely amenable to investi- 
gation if living specimens were available for study. I deter- 
mined, therefore, to give the colony every opportunity for 
cultivating a food fungus. With this in mind the nest was 
kept very moist and there soon developed on the surface of 
the bark two distinctly different fungi. 
The first of these appeared during the initial twenty-four 
hours after the establishment of the artificial nest. It con- 
sisted of numerous, slender, twisted hyphae. These colorless 
strands strongly resembled the filaments of Rhizopus but 
they never formed a heavy mycelium nor, as far as I could 
tell, did they ever produce fruiting bodies. The second fun- 
gus appeared on the following day. It consisted of spherical 
tufts of short hyphae radially arranged around what seemed 
to be a central point of attachment. The diameter of the 
mature colony was about one millimeter and as they ap- 
proached maturity the color changed from white to blue- 
grey. As each tuft seemed entirely isolated and as they 
showed a progressive development through the nest cham- 
bers it seems likely that this second fungus may have formed 
spores although I never saw any. 
During the course of many hours of observation I saw the 
Strumigenys repeatedly crawl around and over each of the 
two fungi. When doing so they would touch the hyphae with 
their antennae but, as they constantly explore their surround- 
ings with these organs while moving, there is no reason to 
attribute special significance to this fact. In no case did I 
see any evidence of the ants feeding on the fungus and it 
was only rarely that the palps came in contact with them. 
It may be argued that neither of the two fungi which de- 
veloped on the bark was the hypothetical food fungus. I see 
