80 THE BIOLOGY OF THE SEASONS 



observed that curlews, godwits, and plovers went 4 miles 

 in one minute a prodigious rate if it could be kept 

 up. It is, however, obviously fallacious to infer from 

 the rate of a sprint how much could be covered in an 

 hour. 



It is interesting to notice Gatke's reference to an old 

 story of Henry ii.'s falcon which escaped from Fontaine- 

 bleau and was captured twenty-four hours later at Malta. 

 Thirty-six miles an hour ! some have said in astonishment ; 

 but the knowing old ornithologist pointed out that the speed 

 must have been at least twice as great. The falcon rested 

 during the night, did a little hunting, had a meal and a 

 digestive rest, and did not hurry after all ! 



Yarrell mentions the fact that in a race from Ghent to 

 Rouen a carrier pigeon flew at the rate of 100 geographical 

 miles in an hour, but Gatke regarded this as a very mediocre 

 performance. By collating observations with John Cor- 

 deaux in England in regard to flocks of hooded crows 

 crossing from Heligoland to Britain, Gatke arrived at the 

 result (certainly open to suspicion) that these birds fly at 

 a rate of 108 geographical miles per hour, doing 320 miles 

 in about three hours. The possible perhaps probable 

 fallacy is obviously that the flocks whose times of starting 

 and of arrival were carefully noticed may not have been 

 the same flocks at all. But 108 miles per hour is nothing 

 like the pace of some other birds! The Northern Blue 

 Throat (Cyanecula suecica), a little bird like a robin, flies 

 in Spring from the Nile and Central Africa (10 to 27 N. 

 lat.) to Northern Europe, to Heligoland by the way. It 

 reaches Heligoland about dawn. Because the bird is very 

 rare in intermediate areas, having only a very isolated 

 occurrence, Gatke concluded that it flies continuously, and 

 there are several other facts suggestive, though not de- 

 monstrative, of this conclusion. At all events, Gatke's 



