332 Recently published Ornithological Works. 



are never (except perhaps the Kittiwake) found more than a 

 few miles from land. If you are leaving, for instance, such 

 a port as Cape Town on a voyage for England, you lose sight 

 entirely of all the Gulls so numerous in Table Bay when 

 only a few miles out to sea. In the other category come 

 the Petrels and Auks ; these are the true sea-birds and may 

 be met with at any distance from the land, and, indeed, 

 seldom come near the land except in the breeding-season. 

 Their food consists entirely of nekton and plankton^ the 

 small organisms which either swim or drift about on the 

 surface of the sea at considerable distances away from land. 



The Black-headed Gull {Larus ridibundus) , now so familiar 

 to Londoners since so many spend the winter and spring on 

 the lakes in St. James's and other parks, penetrates far 

 inland up the rivers, while in the summer it is on its 

 nesting-ground, often many miles from the open sea. 



On the Lake of Geneva the Black-headed Gull is to be 

 found all the year round, and there are probably many indi- 

 viduals which never leave the lake throughout the whole year. 



In contrast to the Black-headed Gull is the Kittiwake of 

 the northern sea ; a true sea-bird, it gets its living from the 

 plankton of the north, disdaining the garbage and offal 

 throAvn up along the shore which satisfies most of the other 

 Gulls. 



From time to time there comes, generally during the 

 Avinter, a great rush of Little Auks to our eastern shores. 

 The birds arrive exhausted, and are picked up in countless 

 numbers dead or dying, not only on the coast but far inland. 

 Dr. Lowe endeavours to explain the " wreck of the Little 

 Auk " by the following chain of reasoning : — The Little Auk 

 feeds almost entirely on the plankton, the surface-floating 

 organisms — small crustaceans, wornos, larval forms of Echi- 

 noderms and Mollusca, which exist in countless millions, 

 especially in the northern seas. The plankton is very 

 sensitive to untoward atmospheric or marine conditions. 

 High winds, cold, excess of fresh water due to melting ice, 

 all tend to drive the plankton to below the surface, and the 

 Auks, unable to procure food and thus weakened, are driven 

 south by the northerly gales in packs and endeavour to find 



