136 BULLETIN OF WISCONSIN NATURAL HISTORY SOCIETY. VOL. 4, NO. 4. 
leaves the nest, and flies around the stem, and up and down along 
the latter, paying much attention to details such as thorns pro- 
truding from the stem, leaves, branches, etc. Thereupon the 
insect takes a look at some other stems or other objects in the 
vicinity, and returns to the nest for further work. After a while 
the bee reappears, goes over the field studied in the previous trip, 
extends its observations over a new stretch of territory, and re- 
enters the nest. In this manner, dividing its time as it does 
between digging and inspecting, the bee gradually increases the 
depth of the gallery, and it also increases its knowledge of the 
topography of the surroundings. By the time the gallery has 
been completed and the bee is able to begin with the storing away 
of pollen and honey in the first cell it has become entirely familiar 
with the locality. When returning to the nest it passes objects of 
different size, shape and color, and its memory of these, as well 
as of the relative position of these objects to one another, makes 
it possible for the bee to find the nest with little difficulty. As 
the days pass by it gains through frequent practice, finally its 
actions become more or less automatic, and it flies swiftly and 
directly to the nest without seemingly taking any notice whatever 
of the objects en route. 
A specimen of Alcidamea prodncta with its nest in a blackberry 
stem was observed at Cedar Lake, Washington Co., Wis., on July 
20th, while at work carrying in the food-supply for a cell. The 
upper portion of the stem containing the nest was protruding 
slightly from a group of blackberry plants, and it was bending 
over so as to be nearly horizontal. The nest-opening was about 
8 dm. above the ground. The bee was bringing in its load of 
pollen and honey about every 9 minutes on the average. 
Two days later, on July 22nd in the forenoon, this same bee 
had provisioned all of its cells, and was engaged in closing the 
entrance to the nest with the customary plug, the so-called "outer 
defense," consisting of a paste of chewed pieces of leaves. On its 
way to the nest it came flying in along the group of blackberry 
plants following a direct course to the nest, and always appear- 
ing from the same direction for the simple reason that the straw- 
berry plant, from the leaves of which it was obtaining its building 
material, was situated in that direction. This bee was certainly 
quite familiar with the locality, and I decided to change to some 
