WHITE-THROATED SPINE-TAIL 213 



preached, the parent birds remain silent and con- 

 cealed at some distance. When the nest is touched 

 or shaken, the young birds, if nearly fledged, have 

 the singular habit of running out and jumping to 

 the ground to conceal themselves in the grass, 



I have no doubt that this species varies greatly 

 in its habits in different districts, and probably also 

 in the number of eggs it lays. Mr, Barrows, an ex- 

 cellent observer, says it lays three or four light blue 

 eggs. He met with it at Concepcion, in the northern 

 part of the Argentine Republic, and writes that it 

 is " an abundant species in thorny hedges or among 

 the masses of dwarfed and spiny bushes, which cling 

 to each other so tenaciously amid the general desola- 

 tion of the sandy barrens." The nests which he 

 describes vary also in some particulars from those 

 I have seen. p< Entrance is gained by the bird," he 

 says, " through a long tube, which is built on to the 

 nest at a point about half way up the side. This 

 tube is formed by the interlocking of thorny twigs, 

 and is supported by the branches and twigs about it. 

 It may be straight or curved ; its diameter exter- 

 nally varies from two to four inches, and its length 

 from one to two feet. The passage-way itself is but 

 just large enough to admit the birds one at a time, 

 and it has always been a mystery to me how a bird 

 the size of a Chipping-Sparrow could find its way 

 through one of these slender tubes, bristling with 

 thorns, and along which I found it difficult to pass 

 a smooth slender twig for more than five or six inches. 

 Yet they not only pass in and out easily, but so easily 



