TEACES OF VOICES IN FISHES. 441 



but little from that described as uttered by the gizzard- 

 shad. Those who may have noticed the vibrating noise 

 made by the wind passing by a number of telegraph 

 wires, will have heard a sound nearly identical. I judge 

 that both sexes utter this sound in concert ; but it may 

 be that during the early spring the sexes separate, to come 

 together again some time later when spawning com- 

 mences, and, in such a case, that only the males " sing." 

 This, however, is scarcely probable in the case of a non- 

 migratory, land-locked species. 



The mullet or chub-sucker is another example of those 

 dull-colored, nocturnal fishes that frequent streams with 

 muddy beds thickly overgrown with water-plants, and 

 which have the power of audibly forcing air from their 

 bodies. In April, with a noticeable deepening of their 

 coloration, there is increased activity in every movement, 

 and, wholly unlike their actions by day, at night they 

 swim quite near the surface, and utter a single prolonged 

 note, accompanied by a discharge of air-bubbles. They 

 appear to project their jaws just above the water, and 

 force the air from beneath their gill-covers immediately 

 below the surface, as there are two parallel streams of 

 bubbles. When seen in the moonlight, these bubbles 

 appear like minute silver beads. Swimming in this way, 

 the mullet will often proceed a hundred yards, uttering 

 their peculiar "call" four or five times while passing 

 over that distance. 



In the lamprey we have a semi-nocturnal species that 

 I have had but few opportunities of observing closely, as 

 it frequents rapidly-running water, and spends much the 

 greater portion of its time under flat stones. On two 

 occasions I have watched them, when mated, and thought 

 that they uttered a peculiar sound, quite unlike any other 

 " fish-note " I had heard ; but it was unaccompanied, so 



