4 INTRODUCTION 



more, then twist into a confused ball, then shoot out straight 

 again, then stop, with a pair of the footprints opposite each 

 other, different from the other end of the track, that began 

 as two or three little indistinct pits or scratches, not forming 

 perfect impressions of a foot. Where the track twisted there 

 are several little round holes in the sand. The whole track 

 commenced and finished upon the open sand. The creature 

 that made it could not, then, have come out of either the 

 . sand or the water; it must have come down from the air a 

 two-legged flying thing, a bird. To determine this, and, next, 

 what kind of bird it was, every one of the trivial points of the 

 description just given must be taken into account. It is a 

 bit of autobiography, the story of an invitation to dine, ac- 

 ceptance, a repast, an alarm at the table, a hasty retreat. A 

 bird came on wing, lowering till the tips of its toes just 

 touched the sand, gliding half on wing, half afoot, until the 

 impetus of flight was exhausted ; then folding its wings, but 

 not pausing, for already a quick eye spied something inviting ; 

 a hasty pecking and probing to this side and that, where we 

 found the lines entangled ; a short run after more food ; then 

 a suspicious object attracted its attention ; it stood stock-still 

 (just where the marks were in a pair), till, thoroughly 

 alarmed, it sprang on wing and was off. 1 



Following the key further, he draws more conclusions. The 

 tracks are not in pairs, so the bird does not belong to the perch- 

 ers ; therefore it must be a wader or a swimmer. There are no 

 web-marks to indicate the latter ; hence it is a three-toed walk- 

 ing or wading bird. It had flat, long, narrow, and pointed wings 

 because it came gliding swiftly and low, and scraped the sand 

 before its wings were closed. This is shown by the few scratches 

 before the prints became perfect. A certain class of birds thus 

 arrests the impetus of flight. It had a long feeling-bill, as shown 

 by the little holes in the sands where the marks became entan- 

 gled ; and so on. These combined characteristics belong to one 

 class of birds and to no other; so he knows as definitely as 



* Elliott Coues, 



