480 TiiE Zoologist — November, 1866. 



substance was apparent in the mouth. The stuff selected is generally 

 very dry stone-dust, a bad building material one would think, but this 

 stuff, when kneaded with the saliva of the bird, forms a cement much 

 harder than if saturated with water. Both soft and dry mud are to be 

 had on the roads, so that this selection of dry material cannot be 

 compulsory : both sexes carry the mud. The martin also builds with 

 the sea-mud gathered in the little tidal harbour of Bullock : the large 

 amount of salt in this sea-mud, one would consider, would make it 

 useless as a building material, as in damp weather it must become 

 more or less moist. I quite agree with White that the house martin 

 copulates in the nest; every observer must have seen a couple of these 

 birds flying into their uest squealing: I have frequently seen two 

 chase one into a nest, and, instead of thinking this a chase after a 

 plunderer, I always considered it two males toying with a female, the 

 cries never at these times indicating anger. I am sorry to have to 

 upset the pretty, though unnatural, theory of the constancy of mated 

 birds; among martins it cannot hold, for many males will enjoy one 

 female while she is collecting mud. Copulation is performed as well 

 on the ground as on the wing and in the nest. 



Sand Martin. — Wc have a very large colony of sand martins at 

 Ballybrack, in this neighbourhood, and as I find their architecture 

 peculiar, some remarks may not be unacceptable. Note-hook. — 

 May 21st, 1862. Visited the sand martin colony, at the sand- 

 banks of Shanganah, to-day, to procure some eggs : I excavated for 

 several nests, having a great demand for eggs this year. The birds 

 are in immense numbers ; there must be more than a thousand pairs. 

 The new holes are generally two feet in depth : great numbers of holes 

 are unfrequented, and, from the immense size of some, must be of very 

 long standing. Of late years the birds build in almost inaccessible 

 places, the holes within reach being generally those of previous years, 

 as I find a new hole almost invariably made each year : those in 

 which you are certain of finding a nest are very small, and require 

 considerable working to enlarge them for the insertion of the hand and 

 arm ; the soil is, however, soft. At the mouths of all the holes are 

 great numbers of fleas, those uninhabited having as many as those 

 which are tenanted : how these birds can incubate among such 

 numbersof blood-suckers, or how the nestlings can live if subjected to 

 their ravages, is to me a mystery. The nests were, without exception, 

 composed of damp sea-weed (I should have stated that the sea nearly 

 washes these cliffs), very shapeless, and lined with a dryer sea-weed, 



