526 PERCHING BIRDS. 



after flock streaming away south in the wake of their predecessors, and many small 

 parties followed the main detachment during the day. The upper-parts of the 

 sand-martin are uniform brown, as is the band on the breast; the lower-parts 

 being dull white. The crag-martin (C. rupestris) spends the summer months 

 among the mountain-ranges of Central and Southern Europe ; as a rule frequenting 

 rocks and old ruins, and nesting in inaccessible places in the month of March, 

 the nests being often placed in the roofs of caverns in the rocks. Mr. Scott 

 Wilson writes that he saw the crag-martin flying about the perpendicular crags 

 of the Gemmi in June 1885, but observed it more particularly and found it 

 breeding on the 1st June 1886 near Meiringen. In the Eastern Pyrenees the crag- 

 martin builds under the eaves of the houses in the centre of the towns, the nests 

 being large structures of mud, quite open at the top, and lined with feathers. The 

 eggs of the crag-martin are white in ground-colour, profusely spotted with pale 

 greyish brown. The general colour of the adult bird is a light ashy brown above : 

 the lower -parts being creamy -buff; and the tail-feathers are dark brown, the 

 central and outer pairs being conspicuously spotted with white. 



Dr. Sharpe divides the swallows into two groups, according to 

 ' the character of the outer primary ; the majority of genera belonging 

 to the smooth- winged group ; while the purple martins (Progne) of America and a 

 few African species constitute the rough- winged group, in which the outer margin 

 of the first primary presents a serrated edge in the adult male. The purple martins 

 are birds of robust and elegant form, possessing a long and stout bill, broad at 

 the base ; long and pointed wings, and a tail much forked. Although they are 

 most numerous in Brazil and the adjoining states of South America, one species 

 summers in the United States, and another is a native of Patagonia. Darwin's 

 purple martin is apparently confined to the Galapagos Islands ; while the Caribbean 

 purple martin is peculiar to the West Indies. The common purple martin (P. pv/r- 

 pu rea) is one of the most familiar of North American birds, and enters the southern 

 borders of the United States as early as February, gradually extending its range 

 over the country, the highest latitudes being reached only in the middle or end of 

 May. In its habits the purple martin differs from most of its congeners in its 

 predilection for nesting in cavities in hollow trees, such as the deserted holes of 

 woodpeckers ; this being especially the case in the Western United States. The 

 nest-cavity is lined with fine stems of grass, leaves, and small twigs, quilted with 

 feathers and other soft substances ; and the eggs are pure white. Several pairs of 

 birds often occupy the same nest, and the majority of couples are double-brooded. 

 The purple martins leave their summer home in August, retreating into the 

 interior of South America. The adult male has the entire body of a lustrous 

 steel-blue ; and the wings and tail bluish black. The female is dark greyish 

 brown, but has the head and back glossed with blue. 



H. A. MACPHERSOK 



