THE PURPLE TRINGA. 195 



quiet and hideling a manner, as the warblers find caterpillars 

 in the groves. That does not hold in the case of the littoral 

 birds only, which run upon the beaches, and never launch 

 themselves on the tide, but with the swimming birds, even 

 with those species of them which at other seasons career 

 over the wide ocean ; for even the storm petrels, the range 

 of whose seaward flight exceeds that of any other birds, 

 remain quiet among the rocks, in the holes of which they 

 nestle, in the breeding season. 



But, in order to keep up the succession, the rock, where 

 it is not progressively built by the creatures themselves (as 

 is the case with the coral worms which build from the bottom 

 of a shallow sea, the sepulchres of one generation affording 

 a base for the dwellings of the next, till they reach the 

 surface), must be annually cleared for a new crop, just as 

 the fields are cleared of annuals, and the deciduous trees of 

 leaves. 



Thus there is, on the tideway rocks, and all against which 

 the roll "of the waters bears strong, what may not improperly 

 be called a fall of the shell, something analogous to the fall 

 of the leaf upon land. When the equinoctial gales set in 

 during the autumn, and all the shallow portions of the sea are 

 in turmoil and fury, ploughing up the sand, scattering the 

 pebbles, tearing up the sea-weed, and assailing the cliffs with 

 battering fragments and washing surges, the number of 

 shells, and other little animals, that are loosened from their 

 moorings, dashed to pieces, or accumulated on the beaches, 

 is beyond calculation, nay, almost beyond fancy. Those 

 animal matters are specifically lighter than the sand and 

 gravel, and, consequently, they are thrown high on the 

 beaches, to the very top of the spring tides, which are then 

 at their maximum, and the littoral birds find them spread 

 out along the shores, just as the field birds find the seeds of 

 plants, which the autumnal winds scatter ; and the accumu- 



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