INTELLIGENCE IN INSECTS 195 
territory in a nearly direct line to her hole—we say nearly 
direct, for there was almost invariably some slight mistake 
in the direction which made a little looking about necessary 
before the exact spot was found. 
“After days passed in flying about the garden—going up 
Bean Street and down Onion Avenue, time and time again— 
one would think that any formal study of the precise locality 
of a nest might be omitted, but it was not so with our wasps. 
They made repeated and detailed studies of the surroundings 
of their nests. Moreover, when their prey was laid down 
for a moment on the way home, they felt the necessity of 
noting the place carefully before leaving it.” Similar 
“locality studies” varying more or less in character, are made 
by many other genera of wasps, but after a number of 
flights from home the preliminary circling about becomes 
gradually reduced, and finally the insects fly away in a 
straight line. 
The réle of visual memory is shown in the way in which 
wasps are disconcerted by a change in the region about their 
nests made during their absence. ‘Aporus faciatus,” say 
the Peckhams, “entirely lost her way when we broke off 
the leaf that covered her nest, but found it, without trouble, 
when the missing object was replaced. All the species of 
Cerceris were extremely annoyed if we placed any new object 
near their nesting places. Our Ammophila refused to make 
use of her burrow after we had drawn some deep lines in the 
dust before it. The same annoyance is exhibited when 
there is any change made near the spot upon which the prey 
of the wasp, whatever it may be, is deposited temporarily.” 
Even a slight change so disconcerted the wasps that they were 
obliged to hunt for a long time before recovering their prey. 
Belt has recorded a very interesting case of a wasp, Polistes 
ecarnifez, which had caught a caterpillar too large to be carried 
