STICKLE BA CKS. 
403 
and from the weather-side. In the daytime they avoid a ship, flying away from 
it; but, during the night, when they are unable to see, they frequently fly against 
the weather-board, where they are caught by the current of air, and may be thus 
carried to a height of some twenty feet above the surface of the water.” In the 
second account, which was published many years ago in Land and Water, the 
author writes that in calm weather flying-fish “ are capable of clearing three 
hundred yards. Their flight is frequently extended to double the distance by 
simply skimming the surface, as a swallow does a pool, and without disappearing. 
I have observed that they never touch the surface more than twice consecutively, 
though they may resume their flight after a period of complete immersion; while 
still in the air, they readily change their course to right angles with their first 
line of flight, or even completely reverse it towards the point from which they 
originally started. I have watched them for hours through a powerful double 
glass, as they rose from either side of the bows of the ship, and noticed that the 
pectoral fins are moved with a slight but very rapid quivering motion, which, I 
have no doubt, assists to sustain them in the air. In rough weather the flight of 
the flying-fish is more rapid, much higher, and of shorter duration than when light 
winds prevail.” This account confirms my own observations as to there being a 
vibratory motion of the pectoral fins when first leaving the water, although the 
writer is probably incorrect in his supposition that this assists the flight. 
Sticklebacks, Flute-Mouths, and Trumpet-Fish, —Families Gastrosteida, 
Aulostomatida, and Centriscida. 
Although the third of the above-named families is regarded by Dr. Gunther 
as forming a group apart, we may follow Day in placing the whole three in a 
single section, characterised by the spinous dorsal fin, when present, being either 
short or formed of isolated spines, and by the generally abdominal position of the 
pelvic fins, which in some instances are imperfectly developed. 
Familiar to every home-born Englishman as the fish upon which, 
Sticklebacks ^ ~ ^ 
in common with minnows, he made his first experiment in angling 
with the aid of a bit of twine, a bent pin, and a worm, the sticklebacks have the 
honour not only of representing a genus ( Gastrosteus ), but likewise a family by 
themselves. Taking their name from the presence of a variable number of isolated 
spines in advance of the soft dorsal fin, sticklebacks have the body more or less 
elongate and compressed, the cleft of the mouth oblique, and the teeth villiform. 
The gill-cover is unarmed, and the cheek covered by the infraorbital bone; and 
in place of scales there are generally large plates along the sides of the body. The 
pelvic fins, although abdominal in position, are connected with the pectoral girdle 
by means of the pelvic bones, and consist of but one spine and a single ray; and 
there are but three branchiostegal rays. Confined to the Temperate and Arctic 
zones of the Northern Hemisphere, where they are represented by some half-score 
species of small bodily size, sticklebacks are mainly fresh-water fishes, although the 
sea-stickleback ( G. spinachia) is a marine or brackish-water form, and all the 
rest can live as well in salt as in fresh-water. The British fresh-water repre¬ 
sentatives of the genus are distinguished by the number of the dorsal spines, and 
