INTRODUCTORY 15 



and never allowed to see a nest typical of their 

 species, or have any communication with old and 

 experienced birds, the results would have been still 

 more startling and strange. 



There is just one more point we ought to mention 

 before finally dismissing the subject of Instinct. We 

 have already seen that the great range of variation 

 in site and materials amongst the individuals of the 

 same species is a most serious and fatal objection to 

 any theory of inherited habit. We have also the no 

 less important fact that the nests of birds of the 

 same species are by no means all of the same excel- 

 lence of construction. In other words, nests are 

 sometimes very indifferently made, some being much 

 more perfectly constructed than others. The sup- 

 porters of the theory of instinct assert that the first 

 nest a bird makes is as perfect as that which it will 

 construct after years of experience. This is a bold 

 assertion, but after all it is no more than the theory 

 inexorably demands, because if the habit is inherited 

 it must be as perfect at the beginning of a bird's life 

 as at the end of it. Unfortunately, however, it is 

 quite at variance with the actual facts. My own 

 observations, as well as those of many other 

 naturalists, do not in the least tend to confirm 

 its accuracy. From a lifelong experience of birds' 

 nests in many localities, I can assert without hesi- 

 tation that at least five per cent, of the nests of any 

 one species selected for comparison are carelessly 



