MIGRATION. 293 



people were all in arms. The banks of the Ohio 

 were crowded with men and boys, incessantly 

 shooting at the pilgrims, which there flew lower as 

 they passed the river. Multitudes were thus de- 

 stroyed. For a week or more, the population fed 

 on no other flesh than that of pigeons, and talked 

 of nothing but pigeons. The atmosphere, during 

 this time, was strongly impregnated with the pecu- 

 liar odour which emanates from the species." 



Captain Flinders relates a somewhat parallel in- 

 stance : he says that while on his voyage he saw 

 " a stream of stormy peterels, which was from fifty 

 to eighty yards deep and three hundred yards or 

 more broad. The birds were not scattered, but fly- 

 ing as compactly as the full movement of their 

 wings seemed to allow ; and this stream of peterels 

 for a full hour and a half continued to pass without 

 intermission, at a rate little inferior to the swiftness 

 of a pigeon. Now taking the stratum of fifty yards 

 deep by three hundred in breadth, and that it moved 

 at thirty miles an hour, and allowing nine cubic 

 inches of space to each bird, the number would 

 amount to one hundred and fifty-one millions and a 

 half." 



The bluebird of America seems to have a power 

 of continuous flight almost equal to that of the swal- 

 low, and among the most interesting of established 

 facts on the subject of migration is that which 

 makes it necessary that this small bird should pass 

 at least six hundred miles over the sea. Wilson 

 says, " Nothing is more common in Pennsylvania 

 than to see large flocks of these birds, in spring and 

 fall, passing at considerable heights in the air, from 

 the south in the former, and from the north in the 

 latter season. The Bermudas are said to lie six 

 hundred miles from the nearest part of the conti- 

 nent. This seems an extraordinary flight for 'so 

 small a bird ; but it is a fact that it is performed. 

 If we suppose the bluebird to fly only at the rate of 

 BBS 



