i4o POPULAR SCIENCE MONTHLY. 



of the chicken. The prison wall is not burst in pieces by spontaneous, 

 random struggles. By a regular series of strokes the shell is cut in 

 two — chipped right round in a perfect circle, some distance from the 

 great end. Moreover, the bird has a special instrument for this work, 

 a hard, sharp horn on the top of the upper mandible, which being 

 required for no other purpose disappears in a few days. Obviously 

 each individual bird no more acquires the art of breaking its way out 

 than it furnishes itself with the little pick-hammer used in the opera- 

 tion; and it is equally clear that a bird could have never escaped from 

 the egg without this instinct. Again, how were eggs hatched before 

 birds had acquired the instinct to sit upon them? Or who will throw 

 light on the process of such an acquisition? Nor are the subsequent 

 phenomena easier of explanation. A fowl that never before willingly 

 shared a crumb with a companion, will now starve herself to feed her 

 chickens, which she calls by a language she never before used — 

 may have never even heard — but which they are born to understand. 

 Once more, it is clearly because she cannot do otherwise that a she- 

 rabbit, when with her first young, digs a hole in the earth away from 

 her ordinary habitation, and there builds a nest of soft grass, lined with 

 fur stripped from her own body. But how as to the origin of this 

 habit? 



We need not accumulate examples of seemingly unfathomable in- 

 stincts. And it may be confessed at once that in the present state 

 of our knowledge it would be hopeless to attempt to guess at the kinds 

 of experiences that may have originally, when the creatures wore 

 different shapes and lived different lives, wrought changes in their 

 nervous systems that, enduring and being modified through many 

 changes of form, have given to the living races the physical organiza- 

 tions of which these wonderful instincts are the corresponding mental 

 facts. Nor, perhaps, can it be confidently asserted that in experience 

 and heredity we have all the terms of the problem. The little we can 

 say is that though in the dark we need not consider ourselves more 

 in the dark as to the origin of those strange instincts than we are con- 

 cerning the origin of those wonderful organs of astonishing and exquisite 

 mechanism that, especially among the insects, are the instruments of 

 those instincts. Nay, more, if the view we have put forward concern- 

 ing the connection between mental manifestations and bodily organiza- 

 tion be correct, the question of the origin of these mysterious instincts is 

 not more difficult than, or different from, but is the same with, the 

 problem of the origin of the physical structure of the creatures; for, 

 however they may have come by their bodies, they cannot fail to have 

 the minds that correspond thereto. When, as by a miracle, the lovely 

 butterfly bursts from the chrysalis full-winged and perfect, and flutters 

 off a thing of soft and gorgeous beauty, it but wakes to a higher life, 

 to a new mode of existence, in which, strange though it may sound, it 



