THK ENTOMOLOGIST. 95 



by always causing the marked ant to cross from the strip of 

 paper (n) to the larvae over a particular bridge of paper (k), 

 and if, whenever a stranger came, the paper bridges (k and l) 

 were reversed, it would be shown whether the other ants who 

 came to the larva? had had the direction and position 

 explained to them. In such a case they would go right, 

 notwithstanding the interchange of the pa])er bridges; but if 

 they found their way by tracking the footsteps of the first ant, 

 they would pass over the paper bridge (k), and thus be led 

 away from the larvae to the strip of paper (i). The result was 

 that out of seventy-nine strange ants, which came up to the 

 point at which the paper bridges diverged, twenty-four went 

 straight along the strip of paper, eleven took the right bridge 

 to the larvae, while forty-four were misled, and went over the 

 paper bridge (k) away from the larvae to the strip of paper (i). 

 He then slightly altered the arrangement, transfixing one end 

 of the two paper bridges by a pin, and so fastening them by 

 one end to the strip of paper (h), the other ends free, that 

 each of them could be turned either to the larvae or to an 

 empty glass tray. When the marked ant came he turned one 

 paper bridge (k) to the larvae, the other (l) to the empty tray ; 

 while whenever any other ant came he turned the bridges, so 

 that K led to the empty tray, and l to the larvae. Under these 

 circumstances, seventeen ants which came along the. strip of 

 paper (h), without a single exception, went over the bridge 

 (k) to the empty tray. He then varied the experiment by 

 leaving the paper bridge (k) louse, as at first; but instead of 

 having a separate bridge (l) he cut the strip of paper (h) into 

 two pieces (h' and h") ; then, when a strange ant was con)ing, 

 he rubbed his finger two or three limes over the bridge (k), so 

 as to remove — or, at least, confuse — the scent. As soon as the 

 ant had passed over the first part(H') of the strip of paper (h), 

 and had arrived on the part (h"), he took up the piece (h') 

 and placed it where the paper bridge (l) had been in the 

 previous experiments, i.e., so as to connect the end of h with 

 the empty glass tray. By this arrangement the bridge K was 

 left in its place, and, on the other hand, there was a bridge 

 which the marked ant had crossed and re-crossed as often 

 as K, but which led away from the larvae. Under these 

 circumstances, out of forty-one ants which (bund their way 

 to the end of the strip (ii), and within two inches of the 

 larvae, fourteen only passed over the bridge (k) to the larvae, 



