ABNORMAL NESTS OF THE SWALLOW. 123 



I have once only seen a Swallow's nest in a cave, and that 

 was inland. The House-Martin will occasionally build in a 

 cave ; in one locality in Anglesea several pairs nested in the 

 roofs of sea-caves a few years ago. The nests were quite in- 

 visible unless one was standing almost directly under them at 

 sea-level. 



The somewhat indifferent photographs here reproduced were 

 taken in winter under difficulties, but they nevertheless give 

 some idea of the position and formation of the nests. The 

 top of the nest on the wall (fig. 1) just shows at the left-hand 

 corner of fig. 2. 



l2 



