THE BIRDS OF HELIGOLAND 355 



in tliis island, often call to mind a much vexed question of recent 

 times, — viz. : — the diminution in the numbers of birds, and the 

 necessity for protection. To a witness, however, of the enormous 

 passage of migrants, of the myriads of individuals which on autumn 

 nights travel past this island, like the Hakes of a snowstorm, not 

 only within the area of the lighthouse, but for miles north and south 

 out to sea, these complaints seem quite incomprehensible. It is 

 surely impossible that the hand of man can exercise any perceptible 

 influence on such enormous migration-streams ; for even if during a 

 certain year, long ago, 15,000 Larks were caught here in one autumn 

 night, this number does not even approximately express a jDroportion 

 of one for each 10,000 individuals forming part of such a migrant 

 stream, extending from to 8 German — 24 to 32 geographical- 

 miles in breadth, and lasting for about seven hours ; and all that is 

 needed for a phenomenal appearance of this kind is that the 

 requisite meteorological conditions coincide with the normal time of 

 migration of a particular species. Such a coincidence has naturally 

 not occurred very often, and has indeed become rarer and rarer in 

 the course of the last thirty years ; when, however, it does occur, 

 all the sjjecies at that particular time are found to be represented 

 in as enormous flights as they were at any previous period, thereby 

 proving that the birds still exist in quantities which exceed all 

 computation. We must, of course, not overlook the fact that the 

 great treasure-house, whence this island derives its immeasurable 

 riches, extends eastward for more than a thousand German, or four 

 thousand geographical miles, and for the most part consists of an area 

 the primitive natural conditions of which have been left completely 

 untouched by the hand of man. To be sure, if after some thousands 

 of years all the land from the Neva to Kamtschatka were to become 

 as thickly populated and as extensively cultivated as central 

 Europe is at the present day, it would indeed be a bad outlook for 

 our little feathered friends ; for where could they possibly betake 

 themselves if they were to be banished from these homes, as they 

 are at present being driven from others — for instance, from Germany. 

 The much-discussed diminution of birds in Germany has not been 

 brought about by their destruction, but by crowding-out. We know 

 how fish have been almost completely l)anished from many rivers 

 by the refuse waters of countless manufactories and overgrown 

 cities. In the same manner agriculture pushed to the utmost 

 limits of productiveness, the cultivation of even the smallest spot 

 of land, the clearance of every bush or shrub, the cutting down of 

 woods, and the clearance of forests, have either destroyed the 

 ancestral homes of our birds, or their happiness and comfort have 

 been so much disturbed by the all-pervading noise of railways, corn- 



