1963] 
Creighton — Cryptocerus texanus 
141 
soon as the texanus workers began to forage over these twigs it was 
obvious that they were feeding. They spent much time licking the tips 
of some of the bud scales of the choke-cherry twigs. An examination 
of these showed that each of the inner scales possesses two oval nectaries 
at its tip. The nectaries produce a fluid which the ants collected. It 
is possible that nectar was also gathered from the willow catkins but 
the obvious thing that the ants took from these was pollen. Their 
liking for pollen was clearly demonstrated, for they would not only 
take it from the catkins but would also spend long hours picking 
up pollen grains that had fallen onto the sides and floor of the aquari- 
um. When the pollen was collected from the sides of the aquaria the 
process was easy to observe but, despite much effort, the writer was 
never able to determine how the grains are initially picked up. It is 
probable that they are formed into clusters by the palps, for the 
mandibles appear to be closed throughout the process. When a number 
of grains have been formed into a cluster this is incorporated into a 
drop of liquid at the end of the hypopharynx. After a short period 
during which the pollen-filled drop is juggled about at the end of the 
hypopharynx, the drop is swallowed. 
As the spring advanced other trees and shrubs came into bloom and 
as each did so twigs with blossoms were placed in the aquaria with the 
texanus workers. It was soon clear that not all pollen is equally accept- 
able to texanus. Although the ants crawled over blossoms of apples, 
plums and Oregon holly ( Mahonia sp.) whose anthers were loaded 
with pollen, they paid no attention to the pollen or to the anthers 
which bore it. Conversely, they were strongly attracted to the pollen 
of the box elder ( Acer negundo L.) and that of the live-oak Q. emoryi. 
The reaction of the ants to the live-oak catkins or to the box elder 
stamens was exactly that which they had shown with the willow cat- 
kins; pollen was collected directly from the catkins or anthers and 
also from other areas where it had settled. This last response sug- 
gested that under natural conditions the ants may secure much of their 
pollen supply not from the blossoms but from other parts of the plant. 
If they prefer wind-borne pollen, as seems to be the case, why might 
not their constant foraging over the surface of the leaves be a search 
for pollen grains adhering to the leaf? The difficulty in proving this 
lies in the fact that over most of the leaf the pollen grains are so widely 
scattered that their detection is difficult, even under high magnification. 
But a careful examination of the leaves of 0 . emoryi showed that a 
considerable concentration of pollen grains is often present in the two 
tangled mats of stellate hairs at the base of the midrib. A great many 
