NATURAL THEOLOGY. 325 



ing hen should look for pleasure from her chickens? 

 It does not, I think, appear that the cuckoo ever 

 knows her young ; yet, in her way, she is as care- 

 ful in making provision for them as any other bird. 

 She does not leave her egg in every hole. 



The salmon suffers no surmountable obstacle to 

 oppose her progress up the stream of fresh rivers. 

 And what does she do there ? She sheds a spawn, 

 which she immediately quits in order to return to 

 the sea ; and this issue of her body she never af- 

 terwards recognises in any shape whatever. Where 

 shall we find a motive for her efforts and her per- 

 severance ? Shall we seek it in argumentation 

 or in instinct ? The violet crab of Jamaica per- 

 forms a fatiguinj; march of some months' con- 

 tinuance from the mountains to the sea-side. When 

 she reaches the coast, she casts her spawn into 

 the open sea, and sets out upon her return 

 home. 



Moths and butterflies, as hath already been ob- 

 served, seek out for their eggs those precise situa- 

 tions and substances in which the offspring cater- 

 pillar will find its appropriate food. That dear 

 caterpillar the parent butterfly must never see. 

 There are no experiments to prove that she would 

 retain any knowledge of it if she did. How shall 

 we account for her conduct ? I do not mean for 

 her art and judgement in selecting and securing a 

 maintenance for her young, but for the impulse 

 upon which she acts. What should induce her to 



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