45 



flight, in very exceptional instances, in Italy, the north of 

 Germany, and in other localities south of the latitude of Heligo- 

 land. This he regards as strong evidence of the unbroken 

 character of the flight. But may not these facts be quite as 

 reasonably cited in evidence of the narrowness of the migrating 

 column ? The paucity of observers in south Europe, too, must 

 not be overlooked. Herr Gatke seems to be quite certain in his 

 own mind that the Bluethroats passing his observatory in spring 

 are identical with those which breed in western Norway. To 

 the writer, however, the evidence is all against the accuracy of 

 this assumption. In the first place we are confronted with the 

 remarkable fact — if such were the case, and if the assertion is 

 correct that these Norwegian individuals occupy the extreme 

 westerly extent of the advancing column— that it is only the 

 latter individuals that take a rest during their flight, though they 

 have the shortest distance to travel. This is a curious circum- 

 stance in view of the statement that the Bluethroat migrates 

 at the rate of 180 miles an hour, and also that by the time 

 it reaches Heligoland it is rapidly nearing its destination in 

 western Norway. Furthermore, this rest appears to be taken at 

 times when the meteorological conditions are most favourable to 

 the performance of an unbroken flight, i.e., during the prevalence 

 of light south-easterly winds with warm weather. If the species 

 migrates in a broad front, how do those individuals dispense with 

 a rest who must, of necessity, travel over the whole length of the 

 Baltic and Gulf of Bothnia, if they rigidly confine their flight 

 between the points of south and north ? One cannot help here 

 remarking on the inconsistency of Herr Gatke's arguments. In 

 the case of the Shore Lark and Hooded Crow, we are told the 

 vast hosts which pass Heligoland can only be derived from a 

 country extending from the Atlantic to the Pacific, but in the 

 present instance, a species, which has always been looked upon as 

 only moderately common, occurs in thousands on one day alone, 

 viz., May 26th, 1880, and, moreover, on a tiny island. In the 

 face of these facts we are asked to believe that these large 

 numbers are journeying north to breed in a very limited area in 

 the most southern and western extension of the breeding range. 

 Does not the above evidence point in a far stronger manner to 



