Instincts, Habits, and Adaptations 47 
discolored, worn, and distorted. The male is humpbacked, with 
sunken scales, and greatly enlarged, hooked, bent, or twisted 
jaws, with enlarged dog-like teeth. On reaching the spawning 
beds, which may be a thousand miles from the sea in the 
Columbia, over two thousand in the Yukon, the female de- 
posits her eggs in the gravel of some shallow brook. The 
male covers them and scrapes the gravel over them. Then both 
male and female drift tail foremost helplessly down the stream; 
none, so far as certainly known, ever survives the reproductive 
act. The same habits are found in the five other species of 
salmon in the Pacific, but in most cases the individuals do not 
start so early nor run so far. The blue-back salmon or redfish, 
however, does not fall far short in these regards. The salmon 
of the Atlantic has a similar habit, but the distance traveled is 
everywhere much less, and most of the hook-jawed males drop 
down to the sea and survive to repeat the acts of reproduction. 
Catadromous fishes, as the true eel (Anguilla), reverse this 
order, feeding in the rivers and brackish estuaries, apparently 
finding their usual spawning-ground in the sea. 
Pugnacity of Fishes.—Some fishes are very pugnacious, al- 
ways ready for a quarrel with their own kind. The stickle- 
backs show this disposition, especially the males. In Hawaii the 
natives take advantage of this trait to catch the Uu (Myrtpristis 
murdjan), a bright crimson-colored fish found in those waters. 
The species lives in crevices in lava rocks. Catching a live one, 
the fishermen suspend it by a string in front of the rocks. It 
remains there with spread fins and flashing scales, and the others 
come out to fight it, when all are drawn to the surface by a 
