ON THE HABITS OF ANTS. 51 



the foot of which was immersed in water. They then ran backward 

 and forward along the paper, trying to escape. If a camel's-hair pen- 

 cil be suspended just over the paper, they pass under it without tak- 

 ing any notice of" it; but if it be scented, say with lavender-water, 

 they at once stop when they come near it, showing in the most unmis- 

 takable manner that they perceive the odor. This sense appears to 

 reside, though not perhaps exclusively, in the antennae. I tethered, 

 for instance, a large specimen of Formica ligniperda with a fine thread 

 to a board, and when she was quite quiet I approached a scented 

 camel's-hair pencil slowly to the tip of the antenna, which was at once 

 withdrawn, though the antenna took no notice of a similar pencil, if 

 not scented. 



On the otlier hand, as regards their sense of hearing, the case is 

 very different. Approaching an ant which was standing quietly, I 

 have over and over again made the loudest and most shrill noises I 

 could, using a penny pipe, a dog-whistle, a violin, as well as the most 

 piercing and startling sounds I could produce with my own voice, 

 without effect. At the same time I by no means would infer from this 

 that they are really deaf, though it certainly seems that their range of 

 hearing is very different from ours. We know that certain allied 

 insects produce a noise by rubbing one of their abdominal rings 

 against another. Landois is of opinion that ants also make sounds in 

 the same way, though these sounds are inaudible to us. Our range 

 is, however, after all, very limited, and the universe is probably full 

 of music which we cannot perceive. There are, moreover, in the an- 

 tenuEe of ants certain curious organs which may perhaps be of an 

 auditory character. There are from ten to a dozen in the terminal 

 segment oi Lasiusflavus, the small meadow ant, and, indeed, in most 

 of the species which I have examined, and one or two in each of the 

 short intermediate segments. These organs consist of three parts : a 

 small, spherical cup opening to the outside, a long, narrow tube, and a 

 hollow body shaped like an elongated clock-weight. They may serve 

 to increase the resonance of sounds, acting, in fact, to use the words 

 of Prof. Tyndall, who was good enough to look at them with rae, like 

 microscopic stethoscopes. 



The organs of vision are in most ants very complex and conspicu- 

 ous. There ai*e generally three eyes arranged in a triangle on the top 

 of their heads, and on each side a large compound eye containing 

 sometimes more than two thousand facets between them. Neverthe- 

 less, the sight of ants does not seem to be very good. In order to 

 test how far ants are guided by vision, I made the following experi- 

 ments : I placed a common lead-pencil on a board, fastening it up- 

 right, so as to serve as a landmark. At the base I then placed a glass 

 containing food, and then put a L. niger to the food ; when she knew 

 her way from the glass to the nest and back again perfectly well, she 

 went quite straight backward and forward, I then took an oppor- 



