CRANES. 



367 



n 



Europe in the month of April or May, passing the fine weather in 



more northern countries. Towards the middle of October, on the 



arrival of the first cold weather, they leave us, in order to winter 



in Egypt, Abyssinia, or even Southern Asia. They travel 



flocks, numbering sometimes 



as many as three or four hun- 



dred birds ; generally they 



arrange themselves in two 



lines, so as to form an isosceles 



triangle, or a sort of wedge 



with the point in front the 



most convenient formation 



for cleaving the air with the 



least amount of fatigue. From 



time immemorial people have 



been fond of saying that these 



birds intrust the care of their 



guidance to a chief, who, after 



having led the way for a 



certain time, and becoming 



wearied, surrenders his charge 



to one of his companions and 



passes to the rear of the 



band, where, like a new Cincinnatus, he resumes the position of 



a simple citizen. The fact is, that the leader of the two files 



changes perhaps ten times in a minute, and the apex of the angle 



is occupied in succession by every Crane in the flock within a very 



short space of time. 



Cranes almost always travel at night, and alight down on the 

 ground during daytime to seek their sustenance. Sometimes, 

 however, they do not stop, and continue to push on through space, 

 giving utterance to startling cries, which probably are intended 

 as a rallying summons to those of the band which seem tempted 

 to linger on their journey. When they perceive a bird of prey, 

 or have to contend against a tempest, they abandon their usual 

 formation, and collect in a circular mass, so as better to resist the 

 enemy. 



Fig " ^- 



