16 TRANSACTIONS OF THE 
NESTING HABITS OF BOMBUS AND OSMIA. 
By Dr. PHILENA FLETCHER HOMER. 
The nests of one of the most common of the western 
bumble bees, Bombus morisoni, are of peculiar interest in 
that they represent a complex type hitherto described only 
from Europe. Several kinds of nests have been described 
by American workers but all are of a simple type in which 
the eggs are deposited in masses of pollen and the only cells 
are the made-over cocoons of the pupae which are used for 
storing honey and pollen. 
B. morisoni, however, not only uses the pupal cases 
as storage cells but in addition builds both brood cells and 
pollen tubes of wax. 
The nest was taken in August, at Logan, Utah. It 
was situated in an old mouse nest under a strawy 
manure pile. The bees had evidently taken forcible posses- 
sion of the nest as the mummified remains of the rightful 
owner were found in one side of the nest. At the time of 
its removal all the stages of bee life were represented, 
from the queen mother to the newly deposited eggs, 
through the young and mature larvae, pupae and the 
recently emerged queens and males. 
The nest was very compact in form and composed of 
four tiers of cells. The lower ones were dark in color 
and mostly used as honey pots. Above there were the 
fresh cocoons containing the pupae and nearly mature 
larvae. These were light brownish in color with papery 
walls stiffened at the base with wax. 
The majority of these cells bore near the apex a 
curious papilliform mass of soft wax which proved to 
be the breeding cells. From three to seven eggs were 
arranged in these cells, perpendicularly with the small end 
downward. A waxen cup is first formed in which the 
eggs are deposited and the cell is then capped over. No 
food was found in any of the brood cells and the young 
probably depend upon the ministrations of the nurse bees 
for their daily rations. 
