2l6 C. H. TURNER. 



there permanently. . . . After days passed in flying about the garden 



— going up Bean Street and down Onion Avenue, time and 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. . . . If the examination of the 

 objects about the nest makes no impression upon the wasp, or if 

 it is not remembered, she ought not to be inconvenienced nor 

 thrown off her track when weeds and stones are removed and the 

 surface of the ground is smoothed over; but this is just what 

 happens. Aporiis fasciaUis 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 Cei'- 

 ceris were extremely annoyed if we placed any new object near 

 their nesting-places. Our Avnnophila refused to make use ot 

 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 placed. We learned from experience how important it 

 was not to disarrange the grass or plants on such occasions." 



All this was written before Bethe ^ had restated, with emphasis, 

 his theory that bees (the morphological and physiological kinship 

 of which to wasps leads one to expect them to be psychologically 

 similar) are guided home by an unknown force ; and before 

 Pieron - had asserted that ants are led home by a reflex kines- 

 thetic sense. This being the state of affairs a crucial experiment 

 seemed to be needed. The mud-dauber {Sceliphroii, Klug = 

 Pelopccus, Latr.) was selected, partly because its habits rendered 

 it comparatively easy to obtain material and partly because, so 

 far as I know, no such experiments have been performed upon it. 



' A. Bethe, " Die Heimkehrfahigkeit der Ameisen u. Bienen zum Theil nach neuen 

 Versuchen," Biol, Centrlbl., 2 Bd. (1902), no. 7, pp. 193-215 ; no. 8, pp. 234-238. 



^ H. Pieron, " Du r61e sense rausculaire dans I'orientation des founnis," Bull. 

 Inst. Gen. Psy. Paris, T. 4 (1904), pp. 168-187. 



