What i instinct? Itis the "faculty of perforuiing complex nota absolutely without iuBtruction, or previously acquired knowledge." Instinct, then, would enable animáis to porform spontaneously acts which in the caso of man, pre-supposes ratiooination, a logical train of thought; but when we test the obseYvpd facts wtiich arfi usually put forward to i prove power of instinct, it is found that they are seldora conclusive. It was on i such grounds that the song of birds wns I taken to bo innate ; albeit vory roady experiment would have shown that it comes from th edncation they receive. During the last ceutury Barrington brought up some linnets, taken from the nest, in ooiapany with larks of sundry varietief?, and found that eveiy ene ol' the linueti adopted computely the song of the luastiT st-t vv J him, so th.it now thea - taPha ly naturnlization - forra a (nmi--,r,v nfHtrt, whfti placpd among birds of their species. Even the nihuritfn , Vís.t -. UHiive .sound is so wem, i-ahitiiu, urutnr di lutit-iition, a eutisufWx) i m ti Mi'iti.if ntler ainging birds, ïhi song of the liird is, theretoie, d(?íeiiiiiu'd hy its trductiúou, and t.ho s.'ini" ij'ir-t bft Tiue hh to nestbuildiug. A birfl brought up in a cage does not oonrtruot tbe nr'St prouüar to ita species. Tn viiin will you snpply all tho ncoessary inateriülsr the hirds will employ thriii without ekill, and will ofteutime even rtnounee all purpose of building anything like a nest. Does not this well-known Hot uove tbat, instead of being guided by instinct, the bird learna how to construct bis nest, just as a man learns hiw to construct a house.