172 INSTINCTS. 



lar to that which sleep bears to night. Against not only the 

 cold, but the want of food, which the approach of winter 

 induces, the Preserver of the world has provided, in many 

 animals by migration, in many others by torpor. As one 

 example out of a thousand, the bat, if it did not sleep 

 through the winter, must have starved, as the moths and 

 flying insects, upon which it feeds, disappear. But the 

 transition from summer to winter, carries us into the very 

 midst of physical astronomy, that is to say, into the midst 

 of those laws which govern the solar system at least, and 

 probably all the heavenly bodies. 



CHAP. XVIII. 



INSTINCTS. 



The order may not be very obvious, by which I place 

 instincts, next to relations. But I consider them as a 

 species of relation. They contribute, along with the ani- 

 mal organization, to a joint eflfect, in which view they are 

 related to that organization. In many cases they refer 

 from one animal to another animal ; and when this is the 

 case, become strictly relations in a second point of 

 view. 



An instinct is a propensity prior to experience, and in- 

 dependent of instruction. We contend, that it is by in- 

 stinct that the sexes of animals seek each other ; that 

 animals cherish their offspring ; that the young quadruped 

 is directed to the teat of its dam ; that birds build their 

 nests and brood with so much patience upon their eggs ; 

 that insects which do not sit upon their eggs, deposit them 

 in those particular situations, in which the young, when 

 hatched, find their appropriate food ; that it is instinct, 

 which carries the salmon, and some other fish, out of the 

 sea into rivers, for the purpose of shedding their spawn in 

 fresh water. 



We may select out of this catalogue the incubation of 

 eggs. I entertain no doubt, but that a couple of sparrows 

 hatched in an oven, and kept separate from the rest of 

 their species, would proceed as other sparrows do, in every 

 office which related to the production and preservation of 

 their brood. Assuming this fact, the thing is inexplicable 

 upon any other hypothesis, than that of an instinct, impress- 



