1928] 
The Bee that Works in Stone 
75 
glistening and opalescent. It is approximately 1.5 mm. in 
length, being about one-fifth as wide as long. 
In looking through the literature, I find no report of any 
bee, or wasp, for that matter, digging its nest out of stone. In 
the study of the thousands of species of wild bees one finds 
many different methods of nesting. The most common of all 
bees, those of the genus Megachile, excavate tunnels, to a depth 
of several inches, in the earth or in other suitable places such 
as the dried stems of pithy plants. In these they construct 
several cells, each about a centimeter long, out of pieces of leaves 
which they cut from nearby plants. These cells are partially 
filled with pollen and honey and an egg is laid therein. This 
hatches and usually takes a year to mature. The process is 
then repeated. Each nest is usually built by but one bee; she 
lives but a month or two. The males never help in the nesting. 
Bees of another genus, Xylocopa, excavate similar tunnels in 
wood and use sawdust to make the cells. Others, of the genus 
Anihidium, find tunnels already constructed, usually in the 
earth. In these, they place cells made of a cottony material 
consisting of hairs scraped from plant stems. Then they fill up 
the tunnel above the cells with the cottony material, soil or 
pebbles, etc., according to the species. And others of the genus 
Dianthidium construct their cells out of a resin which they secure 
from certain plants, such as the sunflower, Helianthus petiolaris. 
Here it occurs in drops on the leaves and stems. Some of the 
species make their cells on rocks, others in the ground etc. Some 
are solitary; others are colonial. One of the latter species even 
keeps two nests going at the same time. See Custer arid Hicks 
(’27). Still others, known as the burrowing bees, such as those 
of the genus Melissodes or Anthophora, dig out extensive galleries 
in the earth. These line their cells with a smooth mud-like 
material probably made by lapping the cell-walls with their 
tongues. Then there are the bees of the genus Osmia that dig 
tunnels in the earth, old logs etc. These construct their cells 
out of macerated plant leaves etc. And, finally, there are bees 
that make no nests at all. They are parasites on other bees. 
Among these we find the genera Coelioxys (parasitic on Mega- 
