REFLEXES, IXSTLMT, AM) lU:.\SON 439 



feinakvs, and for the control of his harcni others are ready at all 

 times to dispute tlie possession. But with niono^ainous animals 

 like the true or hair seal or fox, where a male mates with a single 

 female, there 'is no such diserepancv in size and strength, and 

 the warlike force of the male is spent on outside enemies, not 

 on his ow^n si)ecies. 



The movements of many mijrratory animals are mainly con- 

 trolle:! by the impulse to reproduce. Some pelagic ' >- 



pecially Hying fishes and fishes allied to the mackerel, swim 

 long distances to a region favorable for a disj)osiiion of Hpawn. 

 Some spectes are known only in the waters they mak** their 

 breeding homes, the individuals being scattered th»-ough the 

 wide seas at other times. -Many fresh-water fishes, as trout, 

 suckers, etc., forsake the large streams in the spring, jiscending 

 the small brooks where they can rear their young in greater 

 safety. Still others, known as anadromous fish(»s, feeii and 

 mature in the sea, but ascend the rivers as the impulse of re- 

 production grows strong. Among such s}>ecies are the salmon, 

 shad, alewife, sturgeon, and sirij)ed bass in American waters. 

 Tlie most noteworthy case of the anadromous instinct is found 

 in the king salmon or quinnat of the Pacific coast. This gn'at 

 fish spawns in November. In the Columbia River it begins 

 running in March and April, spending the whole sunimer in 

 the ascent of the river witliout feeding. \\y autumn the in- 

 dividuals are greatly changed in ai)|)earance, discolore(l, worn, 

 and distorted. On reaching the spawning beds, some of them 

 a thousand miles from the sea, the female deposits her eggs in 

 the gravel ©f some shallow brook. After they are fertilizcni 

 both male and female tlrift tail foremost and hel|>h»ss <lown the 

 streini, none of them ever surviving to reach the sea. The ."^iimo 

 habits are found in other species of salmon of the l*acific, but 

 in most cases the individuals of other species do not start so 

 early or run so far. A few species of fishes, as the eel, reverse 

 this order, feeding in the rivers and brackish creeks, dropping 

 down to the sea to si)awn. 



The migration of l)irds has relation to reproduction as well 

 as to changes of weather. As soon as they reach their summer 

 homes, courtship, mating, nest-building, and the care of the 

 young occupy the attention of every species. 



In the animal kingdom one of the great factors in develo|)- 

 jncnt k-a?' l^f'^n the care oj the yoiuvj. This feat urv* is a prominent 



