LECTURE IV. 



HIGHER FORMS OF INSTINCT FOR THE WELFARE 

 OF THE INDIVIDUAL OR THE SPECIES, HAVING 

 NO IMMEDIATE RELATION TO STRUCTURE OR 

 FUNCTION OF ORGANS. 



Intelligence guided by experience, — Instinct independent. — A natural 

 development. — Btdlding of nests or homes. — Perfection of nest 

 no test of the animaFs rank. — The facts of Building stated. — 

 Relation of Building to Structure and Function. — Variation in 

 Building. — Swallows. — Thrushes. — Oriole. — Black - birds. — 

 Sparrows. — Nests fro??i different localities. — Mr, Wallace's The- 

 ory. — Difference in Builditig Power. — Improvement by Practice. 

 — The Cow-bird. — Supplementary Instinct of the Foster-parent. 

 Change of Instinct compared with change in plants. 



Is that Instinct or Reason ? is the common ques- 

 tion, when an animal performs some act that com- 

 mends itself to the Reason of man. Where-we find 

 animals adapting means to ends, the conclusion is 

 often reached that there is Intelligence to guide the 

 act, when the very wisdom of the act proves it to 

 be instinctive, — that is, an act performed without 

 any comprehension by the actor of the end to be 

 reached. Pure Instinct works out the wisest results 

 with the certainty almost of the operations of the 

 physical forces of nature. And because these re- 

 sults are wise, in the sense of being adapted to se- 

 cure the welfare of the actor, and because volition 



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