Spatially Determined Reaction 233 



feature of the bee's visual memory consists in a power of 

 accurately estimating height above the ground. If the 

 entrance to the hive be raised or lowered 30 cm., all the 

 returning bees will go to the old place, and it will be hours 

 and sometimes days before they find the new one. More- 

 over, the same bees tend to return to the same corner of 

 the opening each time. When a row of hives had been 

 arranged, some with openings in front and others with 

 openings at the side, bees which had been driven home in 

 haste by a storm would sometimes try to enter the wrong 

 hive, but if their home hive opened on the side, they would 

 attempt to enter the foreign hive on the corresponding 

 side (115). 



Turner (723 a)?reports that the burrowing bees (Antho- 

 phoridae) use visual landmarks to identify the location of 

 their nests, and are disturbed if the landmarks are altered. 



In the solitary wasps, although Fabre is inclined to as- 

 sume a "special faculty" of homing, independent of visual 

 memory, basing his assumption on experiments where 

 the wasps returned to their nests, from which they had 

 been transported in a box to a distance of three kilometers 

 (218, Series I) ; yet the evidence obtained by the Peck- 

 hams seems fairly conclusive in favor of memory for visual 

 landmarks. The solitary wasps have been shown by the 

 observations of the Peckhams to depend upon sight for 

 the return to the nest (572, 573), and the same conclusion 

 is indicated for the social wasps by Enteman (206). The 

 Peckhams' belief in the visual memory of solitary wasps 

 rests first upon the fact that the wasp, upon completing 

 her nest, always spends some time in circling about the 

 locality, in and out among the plants, as if she were making 

 a careful study of the region. On leaving the nest a second 

 time she omits this process and flies straight away. A 



