Chap. III. MORAL SENSE. 83 



the indirect result of any other faculty ; it must there- 

 fore have been directly acquired. On the other hand, 

 the habit followed by the males of some social animals, 

 of defending the community and of attacking their 

 enemies or their prey in concert, may perhaps have 

 originated from mutual sympathy; but courage, and 

 in most cases strength, must have been previously 

 acquired, probably through natural selection. 



Of the various instincts and habits, some are much 

 stronger than others, that is, some either give more 

 pleasure in their performance and more distress in their 

 prevention than others ; or, which is probably quite as 

 important, they are more persistently followed through 

 inheritance without exciting any special feeling of plea- 

 sure or pain. We are ourselves conscious that some 

 habits are much more difficult to cure or change than 

 others. Hence a struggle mav often be observed in 

 animals between different instincts, or between an 

 instinct and some habitual disposition ; as when a dog 

 rushes after a hare, is rebuked, pauses, hesitates, pursues 

 again or returns ashamed to his master ; or as between 

 the love of a female dog for her yoimg puppies and for 

 her master, for she may be seen to slink away to them, 

 as if half ashamed of not accompanying her master. 

 But the most curious instance known to me of one 

 instinct conquering another, is the migratory instinct 

 conquering the maternal instinct. The former is won- 

 derfully strong ; a confined bird will at the proper 

 season beat her breast against the wires of her cage, until 

 it is bare and bloody. It causes young salmon to leap 

 out of the fresh water, where they could still continue to 

 live, and thus unintentionally to commit suicide. Every 

 one knows how strong the maternal instinct is, leading 

 even timid birds to face great danger, though with 

 hesitation and in opposition to the instinct of self- 



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