124 
PROCEEDINGS OF THE NATURAL [April, 188/. 
least one hundred and fifty wasps in this way, and as we were 
standing over the cage with brushes ready to paint them they 
certainly had every reason to use caution, yet they invariably 
came out head first. 
To see how far their intelligence would aid them in unusual 
difficulties, we once placed acrdss their hole two slender blades 
of grass. 
From 9:00-9:15 a. m., 225 entered, all being hindered bvthe grass. 
“ 9:15—9:20 “ “ 45 “ 
We put on two more blades of grass so that the entrance was 
quite obstructed. 
From 9:20-9:25, forty-eight entered, crawling through the 
grass while one came up as far as the glass and then went back 
into the nest. 
We added eight blades. 
• From 9:25-9:30, forty e„,„ ed . to „, „„ „ „ p „ nd 
We had supposed that such busy, eneqreticcreate . the* 
.aeps seemed to be, would quickly remove anv slight obstacle 
no do. f d "' 0rk ’ ba ‘ " this “» th «y seemed to have 
"f 1 “ ,K° m ? ”.°n ° atte ” ,pt W “ ““J* W remove the blade. 
1"?* 7? '* re > ighte the ordinary load .1 a 
I” 8 ‘ Perh '" , ‘ ‘ hi3 because the, were com- 
ing in, but with no different result *"** ^ “ ** “ ^ 
™ wasps in 
we had under observation at im 7* Wlth the ° ther n8StS that 
Having closed the opening on tZ ^ ^ ™ ^ ^ 
the following morning we poured ^ ^ Z 
cyanide of potassium dissolved ■ h ® nest two ounCeS ° 
immediately closed th,^ ” “ > h » 
out the nest, hoping „ ow lo ohtai ^° Ur “ to ” td we dUg 
points: First, the number of was ns , nf ° rmatlon u P on three 
portion of the different sexes . ‘ ? a nest; seeond > the P r0 ‘ 
and of any undeveloped insects ^ thlFd ’ th ® fate of the maJeS 
