ORNITHOLOGICAL OBSERVATION IN ICELAND. 307 



on the nest, and, during a considerable part of this time, there 

 have been the movements upon it which puzzle me. They 

 include vigorous motions of the tail, and by this I do not mean 

 the rectrices merely, which are bent sharply down, and waggled 

 from side to side, but the whole anal region, the actions exactly 

 simulating those of the male bird (I am here speaking generally) 

 in coitu. The wings are, from time to time, raised and partially 

 opened, and, besides this — a curious point, as it may seem, but 

 which helps me to see a meaning in the whole— the bird some- 

 times seizes twigs of the grass, &c, round about the nest, in its 

 bill. What can such actions as these have to do with turning 

 the eggs ? Eather, it seems a wonder that the eggs are not 

 broken ; but we have here, upon the actual nest itself, and after 

 the proper period of nidiflcation, precisely those movements 

 which both the male and female Peewit, for example, indulge in, 

 during the early spring, in conjunction with a rolling motion of 

 the body, as a result of which small round hollows in. the soil 

 are produced, any one of which might be (and one of which, as 

 I suggest, probably becomes) the actual nest. To my inference 

 that nest-building, amongst birds, has been evolved out of 

 movements of a sexual or sexually induced nature, I need only, 

 in this place, refer ; but the repetition of such actions by a bird 

 sitting upon the completed nest, and engaged in the duty of 

 incubation, would, in that case, perhaps, be explicable, through 

 association of ideas or inherited habit, induced by such an origin. 

 I do not remember coming across any reference to movements 

 of this kind made by birds, whilst incubating. Possibly they 

 may not, heretofore, have been observed, but there is, I believe, 

 a considerable disposition, in field natural history, to put aside 

 facts which do not appear to group themselves with other facts 

 more generally representative of the department under con- 

 sideration, into which they may obtrude themselves, particularly 

 when they do not belong to the more orthodox class of observa- 

 tion or suggest the more usual currents of thought. Such facts 

 interrupt and upset — are a bother, in fact — so as one does not 

 know what to do with them, one forgets altogether about them 

 — gives them the go-by, as it were — but they remain, and remain 

 to be accounted for. 



10.30 a.m. — Since some little time, the bird has turned 



