MIGRATIONS OF BIRDS. 39 



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the rear of a flock. At once, like a torrent, and with a noise like thunder, they rushed 

 into a compact mass, pressing upon each other towards the centre. In these almost solid 

 masses, they darted forward in imdidating and angular lines, descended and swept close 

 over the earth with iuconceivablo velocity, moimted perpendicularly so as to resemble a 

 vast column, and when high, were seen wheeling and twisting within their contiaued 

 lines, which then resembled the coils of a gigantic serpent. 



" Before simset I reached Louisville, distant from Ilardensbui'gh fifty-five miles. The 

 pigeons were stiU passing in undiminished numbers, and continued to do so for three 

 days in succession. The 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 destroyed. For a week or more, the popidation 

 fed on no other flesh tliaii that of pigeons, and talked of nothing but pigeons. The 

 atmosphere, dm-iug this time, was strongly impregnated ^Yith the pecidiar odour which 

 emanates from the species." 



In view of the facts connected with these migrations, the question arises, Why are 

 they undertaken ? " It is not from want of nom-ishment," replies a natm-alist, " for 

 most birds commence their migration while there is stiU abundance in the countrj^ they 

 are leaving. Atmospherical currents are not the caiise, nor do the changes of season 

 explaia it, as the greatest number of them set off while the weather is yet fine ; and 

 others, as the larks and starlings, arrive while the weather is bad. Atmospherical 

 influences can only hasten the migration in autumn, but must rather retard or derange 

 it in spring. It is \he presentiment of what is to happen which detei'mines birds to begin 

 their jom•neJ^ It is an instinct whicli ui-ges them, and which initiates them into the 

 meteoric changes that are preparing. They have a particular faculty of foreseeing the 

 rigoui's of the coining season ; an exquisite sensibility to the perception of atmospherical 

 changes which are not yet arrived, but are approaching." 



Sir Humphry Davy, on the other hand, considers food to be one of the chief objects of 

 these migrations. " Swallows and bee-eaters," Jie saj's, " decidedly pursue flies over half 

 a continent ; the scolopax or snipe tribe, in like manner, search for worms and larvae — • 

 fljdng from those coimtries wherein either frost or dryness prevents them from baring — 

 making generallj' small flights at a time, and resting on their travels where they find 

 food. Hawks are seen in great quantities, in the month of May, coining into the east of 

 Europe, after quails and landrails ; and locusts are followed by numerous birds that, 

 fortunately for the agriculturist, make them their prey." 



Admitting, however, that there is truth in both these statements, we think there is 

 another motive, and one which we cannot but regard as of no ordinary power. All 

 young creatures particularly require compomided aliment, and God appears to have 

 made, in every instance, provision for a supply of fitting nutriments. As birds have not 

 the milky secretion of the mammalia, and as, milike insects, they do not place their eggs 

 where the future progeny will find subsistence, so they are prepared to seek what may 

 be required in distant spots. To quote the words of Mr. Knajip, ^^•ith which we heartily 

 coincide : — " Every one who has made the attempt well Imov\-s the variety of expedients 

 he has resorted to, of boiled meats, bruised seeds, hard eggs, boiled rice, and twenty 

 other substances that nature never presents, in order to find a diet that will nourish 

 them ; but Mr. Montagu's failure in being able to raise the yoimg of the cirl-buntiug, 

 mitil he discovered that they required grasshoppers, is a sufficient instance of the 

 manifest necessity there is for a peculiar food in one period of the life of bii-ds, and 

 renders it probable that, to obtain a certain aliment, the swallow, wren, and others of the 

 insect-eating and fruit-feeding birds, direct their flight to distant regions, and that this 

 is the chief cause of their migrations." 



