INTRODUCTION. 59 



many they are depended on as of much importance 

 in the winter stock of food ; and among the inhabi- 

 tants of the arctic countries, where they are migra- 

 tory, the appearance of the first train of geese is 

 looked for and watched with intense anxiety. 

 Guano, now bearing so much importance as a ma- 

 nure, is the dung of birds belonging to this order. 



In proportional numbers, we have nearly one- 

 third of the whole British birds Natatores. The 

 Tertebrata of Mr. Jenyns, as a recent list (though 

 later investigations have slightly added to it), will 

 serve as a general guide. The total number of 

 British birds enumerated by him, exclusive of 

 twenty-six doubtful species, is three hundred and 

 twelve, of which the Natatores furnish ninety, while 

 the Incessores only muster one hundred and eight, 

 a proportion which could occur in no district ex- 

 cept one situate similarly with our own islands. 

 Of the Natatores, again, one-half nearly is made up 

 of the Anatidce or ducks, there being, according to 

 the above-mentioned list, forty-one species, including 

 the Mergi or Gooseanders. The remainder is chiefly 

 composed of the Lar'idce or gulls, including the 

 terns and petrels ; while the grebes, divers, cormo- 

 rants, and solan-goose make up the remainder. 



