16^ The Irish NatKialist. August, 



happen than in ordinary cases. In the second place, half- 

 fledged young Swallows spend much of their time sitting on 

 the edges of the nest, which, being of cla}', afford them a firm, 

 solid platform, with " elbow room " in abundance. These 

 circumstances quite account for the additional latitude allowed 

 herself b}^ the mother Swallow. A difterent kind of exception 

 is presented by the Golden-crested Wren. This little bird 

 lays, commonly, about nine eggs, in a nest built at some 

 height above the ground in a tree, and this nest is not domed. 

 But, though not domed, it is '^fenced" in a manner ver}^ 

 nearly as protective. Suspended from an overhanging spra}', 

 it is attached at some six or seven separate points to the twigs 

 above it, so that the fastenings form a string of posts, between 

 any two of whicli there is room, as a rule, for the eld bird to 

 slip in and out, but hardly room to allow much danger (unless 

 one of the fastenings breaks) of a young bird being squeezed 

 out accidentall}'. 



Thus I can find no real exception to the rule that five is 

 the maximum number of eggs that a bird can prudently hatch 

 in an open nest of the ordinary type. The use of the dome 

 to those birds that lay larger clutches, as most of our I ri.sh 

 dome-builders do, is therefore obvious. 



The domed nest of the Dipper and the " roofed " nest of the 

 House-Martin ma}', I believe, serve an altogether different 

 purpose. In these cases the natural situation of the nest has 

 to be considered. The Dipper oftens builds where its nest is 

 drenched by the spray of a waterfall, and the inmates would 

 be equally drenched were it not for the cover afforded by the 

 dome. The House-Martin, before the walls of human habi- 

 tations were available for its use, must habitually have con- 

 structed its nest, as some colonies of that species still do, 

 on cliffs facing the sea ; and I think the roofed character of 

 the nest must then have served as protection to the young 

 against drenchings from the spray of high waves. I ma}- 

 here recall Mr. Barrington's note {Irish Naturalist, vol. vi., 

 p. 224), on the nesting of this species at Bray Head, where he 

 remarks that some of the nests seemed to be built within 

 possible reach of waves; and I notice in Mr. Patterson's 

 recentl}' published "Ulster Nature Notes "(p. 51), a some- 

 what similar observation about a colony on the Antrim 

 coast. 



