234 THE SENSE OF SMELL 



about ^ of an inch above the strips of paper along which 

 the ants were passing, in the experiments above recorded. 

 Under these circumstances, while some of the ants passed 

 on without taking any notice, others stopped when they 

 came close to the pencil, and, evidently perceiving the 

 smell, turned back. Soon, however, they returned and 

 passed the scented pencil. After doing this two or 

 three times, they generally took no further notice of 

 the scent. This experiment left no doubt on my mind ; 

 still, to make the matter even more clear, I experi- 

 mented with ants placed on an isolated strip of paper. 

 Over the paper, and at such a distance as almost, but 

 not quite, to touch any ant which passed under it, I 

 again suspended a camel's-hair brush, dipped in assa- 

 foetida, lavender-water, peppermint-water, essence of 

 cloves, and other scents. In this experiment the 

 results were very marked ; and no one who watched 

 the behaviour of the ants under these circumstances 

 could have the slightest doubt as to their power of 

 smell. 



I then took a large female of F. ligniperda and 

 tethered her on a board by a thread as before. When 

 she was quite quiet I tried her with the tuning-forks ; 

 but they did not disturb her in the least. I then ap- 

 proached the feather of a pen very quietly, so as almost 

 to touch first one and then the other of the antennae, 

 which, however, did not move. I then dipped the pen 

 in essence of musk and did the same ; the antenna 

 was slowly retracted and drawn quite back. T then 



