ROUTES 39 



threes or scores, and at night in large numbers. The 

 other is an observation of a " bird wave " by Mr P. 

 Cox, during a snow storm in 1885 at Newcastle, 

 New Brunswick. The birds passed eastward in a 

 column about twenty-five yards wide, some just 

 above the trees, others hardly visible, but the bulk 

 in a massed column directly over the margin of the 

 shore, and not over the river or meadow on either 

 side. The movement was continuous for about two 

 hours. 



Dr I. A. Palmen was the great upholder of routes 

 in the Old World, but his routes were largely specula- 

 tive ; they were founded on a considerable knowledge 

 of migratory birds, but not sufficient to cover the 

 vast area mapped out (39). Until a very large band 

 of workers, working on similar lines all the world 

 over, accumulate a sufficient mass of evidence as to 

 which birds do or do not pass their various stations, 

 with the times at which they appear, accurate know- 

 ledge of the routes of birds is impossible. 



Von Middendorf collected statistics of the passage 

 of birds in the Russian Empire, and by reckoning 

 the average date of arrival of a few species at certain 

 points of observation, worked out a number of curves 

 or lines which he calls " isepipteses," or lines of 

 simultaneous arrival (35). The result was, according 

 to his argument, a general convergence northwards ; 

 the birds passing through Central Siberia travelled 



r 



