68 



Order I 



lays four or five pure white eggs ; the Sand-martin makes 

 a grass or straw nest thickly lined with feathers at the 

 end of a tunnel, which it bores in a bank or even a big 

 heap of sawdust, and also lays white eggs. Sometimes 

 it uses a hole in a wall. 



All these species are migrants, and are with us from 

 about the end of March to November at the latest, 



Sand-martins' burrows 



but the Sand-martin is generally observed first and 

 departs a little earlier ; moreover, it breeds in the 

 Nearctic region, in north-west India, and on the Nile, 

 as well as in the Palsearctic region, while the other two 

 species are confined to the latter. So too it is found in 

 the Neotropical region as well as in the south of the 

 Old World in winter, while the typical forms of the 

 Swallow and the House-martin do not migrate to 



