160 
Psyche 
[September 
the utility of these chimneys, whether they might not be 
built to serve as landmarks for the returning bees. The 
variation in the size, shape and position of these turrets 
was much more apparent than that of the mere apertures in 
the bank. The turrets ran in various directions ; some were 
horizontal, some tilted a little downward, others were at 
various angles toward north and south. There seemed to be 
no plan or scheme of direction, except that none were seen 
with an upward tilt, but the points of the compass were 
utterly disregarded, (see figs. 1, 4, and 8) and so far I have 
been unable to discover any factor, light, convenience, effi- 
ciency, or anything else, that could determine the direction 
in which these chimneys curved as they grew. Their dia- 
meter, (fig. 11) about 1/2 inch outside measurement, was 
fairly uniform for the entire colony, but their length varied 
from nothing to three inches, the greatest number of finished 
ones measuring about two and one-half inches in length. 
None of the tubes were found to be closed either at the 
base or at the orifice of the chimney; the entire channel 
leading down to the cells was in every case hollow, with 
an open groove for its full length along the top. The 
bees did not tear down the chimney and utilize the mate- 
rial for tunnel-filling as do the Odynerus geminus wasps, 1 
nor did they even seal the tunnel with a thin wall 
at the surface of the ground. The tunnels were tor- 
tuous and hard to follow, owing to the closeness of the 
nests and the extreme hardness of the clay. One tunnel was 
opened which slanted downward, then upward, forming 
a letter “V” with a total length of five inches. Another, 
which had a two-inch tube, penetrated the bank to a depth 
of six and a quarter inches, following a zig-zag course, and 
terminated in the usual pocket. This mother evidently had 
lost her nest or had become lost herself before the nest had 
been completed or used. This was not the only case of this 
failing; in a number of cells we found this same condition. 
But these abrupta went further than merely to dig a 
burrow in the ground and provision it, as do so many 
species of their kind. Deep down within the tunnels in the 
i Wasp Studies Afield, p. 299-312, 1918. 
