NESTS AND EGGS, AND NESTLING BIRDS 99 



been adopted by birds in various countries. No finer example 

 of such workmanship could be found than that furnished by 

 the nest of the British long- tailed tit-mouse. The use of such 

 materials secures for the nest a practical immunity from detection, 

 since, so constructed, it harmonises so perfectly with its immediate 

 surroundings as to be almost invisible. 



While the majority of nests are more or less cup-shaped, 

 some are "domed"; that is to say, they are provided with a 

 roof, so that the nest is more or less globular in shape. The 

 nest of the long-tailed tit-mouse is of this kind. The magpie 

 builds a domed nest. Large in size, and composed externally 

 of sticks, this roof is so deftly constructed as to make it almost 

 impregnable save to human egg-stealers. 



Though many birds use mud after the fashion of mortar, 

 to hold other materials together, some species construct their 

 nests entirely of mud. And of such nests no better example 

 could be found than are afforded by our native swallow and 

 martin ; and these will be too familiar to need description. 

 This mud is generally gathered from roadside puddles or the 

 edges of ponds. A certain amount of saliva seems to be used to 

 add to the adhesiveness of the mud. It is interesting, therefore, 

 to note that in certain species of swifts, known as the edible 

 swifts, natives of the islands of the Pacific and Indian Oceans, 

 the glands which form this saliva have so enormously developed 

 as to secrete a flow sufficiently copious to form the whole of 

 the material of the nest. These nests form a valuable article 

 of commerce, being highly esteemed by the Chinese, who concoct 

 therefrom the soup known as birds'-nests soup ! 



The number of instances wherein birds make what may be 

 called a " personal " contribution to their nests is rare. But, 

 in addition to the instance of the swift, we have the practice 

 of the ducks, where the female denudes her breast of down to 

 form a covering for her eggs, and the no less curious custom of 

 some kingfishers the fish-eating species which deposit their 

 eggs on a mass of the bones and other hard parts of the fishes 

 and other creatures which form their prey. These dejecta are 

 thrown up from the mouth in the form of pellets. 



The site of the nest varies much : according to the exigencies 



