PSYCHOLOGY. 45 



distance this does not seem to be a satisfactory explanation. 

 Hearing has been denied to ants altogether by some authors, and 

 it is probable that they do not hear, in the ordinary sense of the 

 word. The possession of chordotonal organs in the tibiae (similar 

 to those of crickets, etc.), and other parts of the body, and the fact 

 that numerous ants possess well-developed stridulating organs, 

 seems however to point to some form of hearing. Lord Avebury 

 could never find that ants seemed to hear any noises of a variety 

 of different kinds which he tested them with, but he considered 

 it probable that they might produce sounds entirely beyond our 

 range of hearing. 



I tested my ants in captivity with the whistle known as the 

 Galton-Edelmann. The human range runs up to 40,000 to 50,000 

 vibrations per second, but tested by the sensitive flame this 

 whistle is seen to give off musical notes far above that limit. I 

 tried my ants in every way with it, up to its highest range, before 

 which no sounds whatever could be heard by me, but the ants 

 never appeared to notice anything at all. 



Wheeler writes on stridulation : " Stridulation, at least among 

 the Myrmicinae, Ponerinae and Dorylinae, is an important means 

 of communication, which Be the has completely ignored and even 

 Forel and other myrmecologists have failed to appreciate. It 

 readily explains the rapid congregation of ants (Myrmicinae) on 

 any particle of food which one of their number may have found, 

 for the excitement of finding food almost invariably causes an ant 

 to stridulate and thus attract other ants in the vicinity. It also 

 explains the rapid spread of a desire to defend the colony when the 

 nest is disturbed." 



I have frequently noticed that when fresh honey is placed in 

 the light chamber of a plaster nest, containing a colony of ants 

 in captivity, after one individual has found it, immediately 

 numerous others pour out and the honey becomes completely 

 covered with feeding ants. Often, it is true, the first ant or two 

 which arrive at the honey return to the nest and appear to tell, 

 and to fetch, others ; but the appearance of such a large number 

 at once seems only explicable as caused by stridulation. Parker 

 and Miss Fielde found that ants reacted to vibrations reaching 

 them through the soil and other solids. They proved that these 

 vibrations were received through the legs, as when the ant's head, 

 gaster, and any one or two pairs of legs had been cut off, it still 

 reacted to them. They conclude their experiments by pointing 

 out that : " It is misleading to ascribe or deny hearing to ants ; 

 they are very sensitive to the vibration of solids, not to those of 

 air ; their reactions could be as appropriately described as resulting 

 from touch as from hearing." 



Several authors however still maintain that ants do perceive 

 aerial vibrations. 



