Pumn Island 



rock. By their free and friendly association, it is 

 evident that these three birds are conscious of a 

 general bond of affinity, and it is therefore the more 

 interesting to note the points in which they differ in 

 their habits. It would seem to be a proof of the 

 non-rational nature of instinct that it is incommuni- 

 cable save by physical inheritance. These birds 

 must have bred side by side for untold ages, and yet 

 no influence of example has ever sufficed to induce 

 the guillemot to place its eggs in a hollow like the 

 razorbill, or the razorbill to adopt the still greater 

 security of a burrow like a puffin. Yet, on the 

 assumption that birds so similar in other respects 

 have had a common origin, there must have been a 

 time when the habits of the common stock were 

 identical. If nothing but a non-rational instinct 

 obtained among that common stock, whence the 

 present divergence in habits ? That the birds co- 

 operated unconsciously in the formation of their 

 different habits would seem to be borne out by the 

 fact that, after ages of intimate association with the 

 razorbills, the guillemot is still at infinite pains 

 pains as, in the literal sense of the word, they must 

 often be to keep its eggs from falling over the 

 ledge upon which it continues to deposit it. Rigid, 

 with its face to the rock, and its legs braced to keep 

 it in position as it covers its egg, the bird seems 

 unable to grasp the simple fact that if it were laid 

 in a hollow it would not roll, and might be hatched 

 in comfort and security. One cannot appeal to 



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