298 ANIMAL INTELLIGENCE. 



of this large body of water from the second pond caused a rise 

 of several inches, so as to threaten the speedy immersion and 

 consequent destruction of the eggs. This the birds seem to 

 have been aware of, and immediately took precautions against 

 so imminent a danger ; for when the gardener, upon whose 

 veracity I can safely rely, seeing the sudden rise of the water, 

 went to look after the nest, expecting to find it covered and the 

 eggs destroyed, or at least forsaken by the hen, he observed, 

 whilst at a distance, both birds busily engaged about the brink 

 where the nest was placed ; and when near enough he clearly 

 perceived that they were adding, with all possible despatch, fresh 

 materials to raise the fabric beyond the level of the increased 

 contents of the pond ; and that the eggs had by some means 

 been removed from the nest by the .birds, and were then de- 

 posited upon the grass about a foot or more from the margin of 

 the water. He watched them for some time, and saw the nest 

 rapidly increase in height ; but I regret to add that he did not 

 remain long enough, fearing he might create alarm, to witness 

 the interesting act of replacing the eggs which must have 

 been effected shortly after ; for, upon his return in less than an 

 hour, he found the hen quietly sitting upon them in the newly 

 raised nest. In a few days afterwards the young were hatched, 

 and, as usual, soon quitted the nest and took to the water with 

 then* parents. The nest was shown to me in situ shortly aft^r, 

 and I could then plainly discern the formation of the new with 

 the older part of the fabric. 



We must not conclude these remarks on nidification 

 without alluding to Mr. Wallace's chapters on the ' Philo- 

 sophy of Birds' Nests,' in his work on * Natural Selection.' 

 This writer is inclined to suppose that birds do not build 

 their nests distinctive of their various species by the teach- 

 ings of hereditary instinct, but by the young birds intelli- 

 gently observing the construction of the nests in which 

 they are hatched, and purposely imitating this construc- 

 tion when in the following season they have occasion to 

 build nests of their own. With reference to this theory 

 it is only needful to say that it is antecedently improbable, 

 and not well substantiated by facts. It is antecedently 

 improbable because, when any habit has been continued 

 for a number of generations — especially when the habit 

 is of a peculiar and detailed character — the probability is 

 that it has become instinctive ; we should have almost as 



