Vol i8^ IH ] Allen, Gatkes 'Heligoland: 143 



individuals which pass on from Africa to the Scandinavian penin 

 sula, including the majority of the representatives of the species, 

 "accomplish during the same May night a distance of 2000 to 

 2400 geographical miles. This would," he adds, "of course, 

 give as a result a velocity of four miles a minute," or 240 miles 

 an hour ! 



Whatever the Bluethroat may really do, the kind of migration 

 ascribed to it is not that well known to characterize the majority 

 of birds during the spring migration; indeed, Heir Gatke finds it 

 necessary to explain away the observations of others, or to dis- 

 regard such of their testimony as may be known to him, as of no 

 special importance when weighed in the scale with his own "fifty 

 years' experience " on the little island of Heligoland. Thus he 

 says: ''It has been supposed that birds are in the habit of break- 

 ing their migration journey without any very powerful disturbing 

 cause both in autumn and spring, at the former season on reaching 

 latitudes not. so far south as those of their normal winter quarters, 

 and in spring before they have arrived at their breeding stations. 

 With this assumption, however, my own experiences on ///is island, 

 accumulated for many years, are at variance." This quotation, 

 especially the portion here italicized, shows the attitude and spirit 

 in which Giitke approaches the many general questions he dis- 

 cusses, — his own little island of a few acres in extent, nearly 

 woodless and barren, and his own experiences limited thereto, 

 being placed in opposition to the accumulated experience of 

 thousands of observers scattered over the greater part of the earth. 



It is quite possible that many birds, the Plovers among them, 

 attain not unfrequently a speed of 100 to 150 miles per hour, and 

 are able to maintain that rate for a number of consecutive hours, 

 but that birds as a rule fly at this rate, or make the journey 

 between their winter stations and breeding grounds " in one unin- 

 terrupted flight" is not by any means the rule, if indeed it be 

 the case in any instance. To marshal the well-known proof of 

 this would be almost to insult the intelligence of the experienced 

 ornithologist. Let it suffice to say that where trustworthy obser- 

 vations have been made regarding the ordinary flight of Ducks, 

 Pigeons, Hawks, and some other species, the rate of speed has 

 been rarely found to exceed 35 to 60 miles per hour. 



