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more disturbed. Once they had little to fear, as the 

 surrounding marsh defended them from all the carni- 

 vorous surrounding quadrupeds, and their own strength 

 from birds of prey; but by along series of alarms, 

 they have, at length, been obliged to seek, during the 

 summer, some lonely habitation, at a safe distance from 

 every destroyer. 



Of the numerous tribes of the Duck-kind, we know 

 of no more than five that breed here. The rest con- 

 tribute to form that amazing multitude of water-fowl 

 which annually repair to the dreary lakes and deserts 

 of Lapland, -from the more southern countries of Eu- 

 rope. In those solitary retreats, they perform the 

 duties of incubation and nutrition in full security. 

 There are few of this kind that may not be traced to 

 the northern deserts, to countries of lakes, rivers, 

 swamps, and mountains, covered with thick and gloomy 

 forests. In those regions, from the thickness of the 

 forests, the ground remains moist and penetrable 

 during the summer season ; the woodcock, the snipe, 

 and other slender-billed birds, can there feed at ease, 

 while the wcb-footrd birds find more than sufficient 

 food from the number of insects which swarm to an in- 

 credible degree. The days thsre arc long, and the 

 beautiful nights afford them e\ery opportunity of col- 

 lecting so minute a food. 



2. Birds have feathers which they expand in order 

 to llv, the fine branches of which lie so close together, 

 that little air can insinuate itself between them. Now 

 when the column of air on which a body rests is speci- 

 fically heavier than the body, it remains suspended iu 

 the air; if it be lighter, the body sinks. Hence the 

 larger space a body circumscribes, the more easily docs 

 the air sustain it: consequently the same bird which 

 sinks when the wings are closed, is sustained when 

 they are expanded. To this also the motion of the 

 wings contribute : (as a body while moving swiftly 

 will swim in water^ which immediately sinks if inat 



