XIII SOUND-PRODUCING ORGANS 363 
ear of the observer two metres above the water; and it has been 
recorded that by listening for these sounds, shoals of Maigres have 
been successfully netted. They rarely emit sounds when isolated ; 
but in shoals, during the breeding season, they do not cease to 
make sounds with a vigour and a persistency which apparently 
must soon wear out their strength. One of the Indian Horse- 
Mackerels (Caranz hippos) grunts like a young Pig when captured, 
and the sound is repeated whenever it is moved, as long as vitality 
remains. A West Indian species of the same family (Argyriosus 
vomer) has been observed to produce a lke sound, while an 
Egyptian Caranx (C. rhonehus) is known to the Arabs as the 
“Chakoura” or “Snorter.”’ The sounds produced by the 
different British Gurnards, such as the Grey Gurnard (77rigla 
gurnardus), the Piper (7. lyra), the Elleck or Cuckoo Gurnard 
(7. cuculus), and the Tub-Fish (7. hirwndo), have been compared 
to snoring, a sonorous and prolonged grunting, crooning (whence, 
perhaps, the term “crooner,” by which the Grey Gurnard is known 
in Ireland), and croaking. The John Dory (Zeus faber)” also 
utters sounds analogous to those of the Gurnards. Among the 
Dipnoi Lepidosiren is said to make a growling sound, and Weo- 
ceratodus a grunting noise which may be heard at night for 
some distance. 
Whatever the nature of the vocal mechanism, it is highly 
probable that the sounds produced by Fishes travel to considerable 
distances in the water, inasmuch as the latter medium is a far 
better conductor of sound than air, and, moreover, the transmission 
of sound-vibrations from the air-bladder to the water is facilitated 
in many Fishes by the fact that, for a portion of its extent on 
each side the bladder is in direct contact with the superficial skin 
behind the pectoral girdle. 
From the by no means exhaustive list of examples given above, 
it is obvious that in some form or other vocal organs are present 
in a considerable number of Fishes, both freshwater and marine, 
belonging to widely different groups; and further, that even in the 
same species (e.g. Doras maculatus and other Siluridae), both 
stridulation and the action of extrinsic muscles on the air-bladder 
may be utilised as a means of sound-production. Certain 
Teleostean families like the Siluridae, the Sciaenidae, and the 
Triglidae, seem to be distinguished above all others by the pre- 
1 Sorensen, op. cit. 2 Moreau, op. cit. 
