4 
Psyche 
[March 
quantities were pipetted into vials (4.5 cm. long by 1.3 cm. in dia- 
meter) with an inner lining of filter paper. Each vial was placed in a 
cylindrical screen cage 10 cm. long by 3 cm. in diameter, which was 
EXTRACT (ml.) 
Figure 1. Attraction of worker bees to an extract of bee stings in methy- 
lene chloride. The extract was pipetted onto filter paper and introduced in 
screen cages laid over the combs of a colony. Bees attracted to each cage 
were collected and counted. 
open at one end. The cages were laid in groups of four across the top 
bars of an open colony, immediately enclosed by an empty hive body 
and cover, and left in this dark chamber for 3 minutes. Each was 
then carefully transferred with the adhering bees into a closed con- 
tainer. The bees thus collected were anesthetized and counted (Fig. 
1 ) . Although the data show considerable variation, there was a 
positive correlation between the quantity of extract per vial and the 
number of bees attracted. 
An extract containing about 5,000 stings in 10 ml. of methylene 
chloride was distilled, beginning at 35 0 C. and slowly rising to 90° C. 
The colorless distillate was collected in three approximately equal 
fractions. The last two fractions, distilled at temperatures over 
