SOLITARY AND GREGARIOUS. 41 



set and disposed to give signal by their manner of 

 cry, for to range orderly in ranks, and keep close 

 together in array : and this they do by turns each 

 one in his course. They maintain a set watch all 

 the night long, and have their sentinels. These 

 stand on one foot, and hold a little stone within the 

 other, which by falling from it, if they should chance 

 to sleep, might awaken them, and reprove them for 

 their negligence. Whiles these watch, all the rest 

 sleep, couching their heads under their wings ; and 

 one while they rest on the one foot and otherwhiles 

 they shift to the other. The captain beareth up his 

 head aloft into the air, and giveth signal to the 

 rest what is to be done*." 



The old grammarian, Johannes Tzetzes, has ren- 

 dered this story into Greek verse; and the historian, 

 Ammianus Marcellinus, tells us, that in imitation of 

 their ingenuity, to ensure vigilance, Alexander the 

 Great was accustomed to rest with a silver ball in his 

 hand suspended over a brass bason, which, if he 

 began to sleep, might fall and awake himf. 



The golden plover (Charadrius pluvialis, TEM- 

 MINCK) is another bird celebrated for setting a watch. 

 Longolius says these birds are so attached to 

 society, that a single bird is never seenj. Belon 

 gives a minute account of their proceedings, which 

 we shall translate. " The plovers," says he, " call 

 to one another at day- break, whistling in a manner 

 similar to that of a man, and answering to the word 

 hinc. The peasants, hearing this, try the next day 

 to discover a covey ; for the plover by day remains 

 in society, but at the approach of night strays from 

 his flock, and on the following morning his com- 

 panions are scattered about at a quarter or half a 



* Holland's Plinie, x. 23. 



f Apud Aldrovandi Ornith. iii. 137. 



$ Apud Aldrovandi, iii, 206. 



E3 



