OPEN NESTS 151 



same model of sticks and twigs, lined with green 

 herbage ; or if the breeding-place is near reed-beds, 

 broken reeds are often intermixed with the sticks. 

 Lastly, when built in trees the nest is chiefly com- 

 posed of a huge mass of sticks, the cavity being 

 lined with green herbage. The whole structure is 

 more or less coated with droppings and remains of 

 fish. The nests of the Shags have already been 

 alluded to, as they generally occupy a covered site. 

 Cormorants, we should say, are more or less 

 gregarious during the breeding season, some of their 

 colonies containing many hundreds of nests, and 

 these places are used season after season. The 

 nests of the nearly allied Snake Birds, or Darters 

 (Plotidae), are very similar, generally being placed 

 on trees and formed of sticks, the cavity being 

 lined with roots and moss. These curious birds, of 

 which but three or four species are known, are 

 tropical or sub-tropical in distribution, and are found 

 round the world in these latitudes. They have the 

 same gregarious and social habits as their allies. 

 The nests of the Pelicans (Pelecanidse) do not differ 

 in type from those of the other birds in this order, 

 and are either made upon the ground amongst reeds 

 in marshes, or placed upon trees. Nor do we find 

 anything exceptional in the nesting arrangements 

 of the Frigate Birds (Fregatidse). But two species 

 are known confined to the tropics and the Southern 

 Hemisphere. These birds make rather slight nests 



