Natural History of the Honeybee. 21 



can be no doubt at all that bees find their way back to the hive, not by means of memory 

 pictures' ' (Bethe, p. 89). 



I cannot find in the foregoing the slightest foundation for this view of Bethe 's. If 

 he wishes to disprove the investigations of Bomanes, 63 then I think the attempt is unsuc- 

 cessful, for Bethe leaves to us the proving that the city has remained actually ' i unknown ' ' 

 to the bees. 04 



But how is the mysterious behavior in the streets explained? We shall let Bethe 

 speak for himself: "All bees, if let fly, go upward in a corkscrew line, then suddenly 

 take a direction and" fly off in a straight line. This happens when bees are let fly in the 

 city streets almost always before they have reached the levels of the house roofs. It often 

 happens at a height of four to six meters above the street level, therefore generally before 

 they can have acquired a view of the neighborhood. Now, almost without exception, they 

 take the direction of the Institute, where the hives are. ' ' 



Before I give the explanation for this, other parts of Bethe 's account continue: "Light 

 is the incentive to flight in these diurnal animals" (Bethe, p. 83) ; further, "Light regulates 

 flight." 



I remember, too, in Herm. Miiller's investigations that he could' carry a bee in a 

 drinking-glass open beneath, the length of the garden without the bee flying out, for it 

 constantly pressed to the top of the glass toward the light. 65 



I slipped a bee into a reagent glass and put it upon the window-sill so that the bottom 

 of the glass was toward the window. For eight hours the bee strove inside the glass in 

 vain efforts to reach the light. Then it died, although it would have been easy to crawl 

 out of the open tube and fly out of the open window. 



Now, if we remember that the city lies to the north of the seat of Bethe 's investi- 

 gations, we shall see that the sun must be in the direction of the Institute, and the 

 bees were let fly in "quiet, sunny weather" (Bethe, p. 87). In the darker streets, perhaps 

 unknown to them, they tried to orient themselves by mounting in circles, just as a 

 carrier pigeon does. 66 Then they fly instinctively toward the bright source of light (just 

 as in a room they fly unfailingly toward the bright window) until they become oriented 

 in familiar regions. "Light regulates flight" (Bethe, p. 83). 



I, therefore, can not consider the "unknown force" and the conclusions based on it as 

 capable of proof. 



I have held to Bethe 's assertions with regard to* these directions. From them I 

 understand that on one side of the Institute toward the soutfy are the meadows; and on 

 the other (therefore toward the north) is the city. Possibly Bethe did not liberate the 

 bees just in the center of the city but toward the edge, so that the Institute was shifted 

 from its southern position a little toward the west or east. Further investigations might 

 be necessary, perhaps, to prove that these bees did not return to the hive not through the 

 "unknown force." 



We learn from Bethe (1. c, p. 87) that eight marked bees were let fly in the* city 



63 Romanes, Nature, 1885, Vol. 32, p. 630, Homing Faculties of Hymenoptera. 



64 That Bethe' s idea that bees had not been flying in the city is not at all convincing, follows from 

 something written by the editor of "Elsass-Lothring. Bienenzuehters." Karl ZwiUing, which reached 

 me subsequently. In my publication in the "Biologischen. Centralblatt" the same is given, therefore, in 

 a later passage. I quote the following: "* * * Outside of Strassburjg there are many apiaries close 

 to the wall, the bees of which never think of flying into* the city except in times when there i$ no 

 forage. Then they enter the candy factory of Mr. Pale, Tiergarten Strasse, and annoy the workers as 

 well as partake of the sweets. Even in the month of December, 1899, in the warm sunshine I observed 

 bees flying in the middle of the city on the Kleberplatz, where hundreds of pots of flowers were dis- 

 played for sale. There they gathered honey and pollen. Every year some swarms fly into Strassburg 

 and hang on the chestnut, linden, oak, and. - locust trees found in many parts of the city, and once a 

 swarm hung on the showcases of a glovestore near the cathedral. "When the trees bloom, bees fly 

 about them vigorously. In the interior of the city there are beautiful rows of chestnuts along the 111, 

 rows of lindens around the Kleberplatz, etc., all of which are sought out by the bees when they are in 

 bloom. The honey-venders and those who deal in sugar wares are not molested if they keep their wares 

 covered. As I live in the neighborhood of Strassburg (ten minutes by rail), and have been President 

 of the Bienenverein there for thirty years, I know the conditions exactly." 



85 Herm. Muller, Versuche uber die Farbenliebhaberei der Honigbiene, Kosmos, Jahr. 6, p. 276, 1882. 

 66 H. E. Ziegler, Die Geschwindigkeit der Brieftauben, Zoolog. Jahrb., X. Bb., 1897, pp. 99, 278. 



