April, 1887.] history society of Wisconsin. 
107 
We now substituted for the nasturtiums some escholtzia blos¬ 
soms which nearly matched the yellow paper in color. 
From 10:15-10:20 only 6 out of 173 noticed the flowers. 
“ 10:20-10:25 of 153, 9 noticed flowers. 
“ 10:25-10:30 “ 156,6 “ “ 
We now changed back to the dark red nasturtiums. 
From 10:32-10:37 of 141, 25 noticed flowers. 
As the nasturtiums had a strong perfume and escholtzia none 
at all we thought that the wasps probably visited the nastur¬ 
tiums because they smelled them rather than because they saw 
them. To settle this point we took three light yellow nastur¬ 
tiums which matched the paper even more nearly than the 
escholtzias and placed them as before, two inches from the hole, 
removing the other flowers. 
From 11:00-11:05 of 72 wasps 3 visited nasturtiums. 
“ 11:05-11:10“ 38 1 “ “ 
“ 11:10-11:15“ 32 “ 1 “ 
“ 11:15-11:20“ 42 “ none “ 
The wasps, then, were even less attracted by the light yellow 
nasturtiums than by the odorless escholtzias, while the dark red 
nasturtiums were visited much more frequently than either. As 
the light nasturtiums were as fragrant as the dark ones we con¬ 
cluded that it was the color, not the odor, which attracted the 
wasps to the flowers. 
On the same day (August 11) at 10:30 a. m. we substituted 
for the yellow paper one of light green which, m the sunlight^ 
had yellowish reflections. From 11:30-11:40 of 1/2 wasps 100 
clearly noticed the change but in not nearly so marked a man¬ 
ner as they had the other changes. 
On the following day, August 12: 
From 8:30-8:36 a. m. of 100 wasps 2 hesitated before entering. 
“ 8:36-8:41 a. m. of 200 “ 9 “ 
On the same day at 8:50 a. m. we substituted a red paper for 
the green. 
From 8:50-9:10 of 191 wasps 107 noticed the change. 
“ 9:10-9:15 of 187 “ 112 “ 
