stridulation in ants. 213 
means the same thing as ‘‘hearing” in man. The organs 
of the higher senses in insects are so profoundly different 
from those of man, and the nerve communications and 
centres are so fundamentally distinct, that a particular 
sound to an insect may be a totally different thing to 
what it isto us; hence, though it is known that ants are 
deaf to many sounds we hear, it is none the less probable 
that they may hear where we are deaf. Very little is at 
present known as to the organs of hearing in insects 
other than Orthoptera, and when they are known we 
may be sure that there will still be great difficulty for us 
in realising what an insect really hears. Still, I think 
the difficulties will not be so great as they are in the 
case of the ocular organs and sense of sight. 
EXPLANATION OF PuatE IX. 
Fic. 1. Portion of the dorsum of the articulating neck of third 
abdominal segment of Dinoponera grandis (worker), showing the 
stridulating file and contiguous sculpture. 
Fic. 2. Hind margin of second abdominal segment of Dino- 
ponera grandis, showing the margin crenulated, except at a, which 
passes over and scrapes the file. 
Fic. 8. Dorsal surface of articulating neck of third abdominal 
segment of Ponera contracta, showing the articulating file and 
contiguous sculpture. 
Fic. 4. Stridulating organ of Ponerid from Tasmania, showing 
the file on third segment, and the edge (displaced) a, of the second 
segment that scrapes the file (worker). 
Fie. 5. File of Sima ?, from Australia (worker). 
Fia. 6. File of Myrmicid, from Amazons Valley (2). 
Fia. 7. File of Atta, sp., from Guatemala (worker). 
