168 EXPERIMENTS TO TEST 
other strips f and g, in such a manner that they can be 
freely turned round, so that each can be turned at will 
either to A or m. Under ordinary circumstances the 
paper f, as in the figure, was turned to the larve ; but 
whenever any ant, excepting the marked one, came, I 
turned the papers, so that f led to m andgtoh. The 
result was striking, and I give the observation in full 
in the Appendix. In all, 17 ants came, every one of 
whom took the wrong turn and went to m. 
Although the observations above recorded seem to 
Fig. 5. me almost conclusive, still I varied the 
experiments once more (see fig. 5), 
making the connexion between the 
board B and the glass containing the 
larve by three separate but similar 
strips of paper, d, e, and f, as shown in 
the figure. Whenever, however, a 
strange ant came, I took up the strip f 
» and rubbed my finger over it two or 
three times so as to remove any scent, and then-re- 
placed it. As soon as the stranger had reached the 
paper e, I took up the strip d, and placed it so as to 
connect ¢ with the empty glass m. Thus I escaped the 
necessity of changing the paper f, and yet had a scented 
bridge between e and m. The details, as before, are 
given in the Appendix. 
In this experiment the bridge over which the 
marked ant passed to the larve was left in its place, 
the scent, however, being removed or obscured by the 
