ANT COMMUNITIES 



However, the ordinary listener should not be dis- 

 appointed if he fail to hear these stridulatory notes, so 

 delicate and faint are they. They belong to that occult 

 realm of sights and sounds into which few of the more 

 highly organized forms of life are privileged to enter, 

 and not to the great company of insect musicians who 

 fill our summer and early autumn fields and woods with 

 their varied orchestration. 



One who carefully observes the abdomen of a large 

 ant, even with the naked eye, can see that it is made up 

 of segmental plates, five above (dorsal) and five below 

 (ventral). These plates are imbricated that is, they 

 overlap one another, like tiles on a house-roof. They are 

 composed of epithelial scales, hexagonal in form, which 

 present a beautiful appearance, as of delicate mosaics, 

 when viewed through a microscope. When a profile 

 view of one of these scales is exposed to the lens the 

 serrate edge is clearly seen. Thus it is plain that a 

 backward and forward motion of the plates upon one 

 another might produce a faint rasping sound. All that 

 is required for the complete conditions for stridulation is 

 the muscular ability to perform this action rapidly (Fig. 

 06). Ants certainly possess this; and, in fact, they may 

 be seen thus moving the abdominal plates in and out, 

 back and forth, with a rapidity that seems to increase 

 with their excitement. The many faint sounds thus 

 made, inaudible in the individual, but audible in the aggre- 

 gate, would account in part, at least for the peculiar 

 hiss-z-z-z which arises from an excited column or colony 

 of ants. It will also help to explain the popular belief 

 that one sometimes picks up in rural parts, that u ants 

 sing." Besides this grating of the abdominal plates over 

 one another, there is a rotary movement of the base of 



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