190 THE ZOOLOGIST. 



these birds passed the Koek most often in small parties ; less 

 typical links in the chain being formed by solitary travellers. 

 By making careful and protracted observations with the aid of a 

 pair of strong prism binoculars, I was able to see that the 

 migrants were often spread out on either side ; and, no doubt, 

 beyond the range where I could descry their presence, they, as 

 part of the stream, were heading in the same direction. Hence 

 it might be more appropriate to designate this streaming mass 

 of migrants as moving in a broad procession, loosely and unevenly 

 marshalled. Call it what one will, there remains the important 

 fact that vast numbers of birds — all heading in the one direction, 

 all moving in an orderly fashion, and all exhibiting the same 

 steady and uniform speed of flight, so that one bird was seldom 

 seen overtaking its companion — were performing a natural and 

 quite undisturbed migration, a migration which went on for 

 many consecutive days during a given time of the year, only 

 interrupted spasmodically by haze, which held the voyagers up, 

 or by storm which drove them back to alight on the shore or on 

 rock-islands, en route. And without particularizing in regard 

 to species, I have little doubt that when undisturbed by adverse 

 weather, whether it be haze or storm, and when not allured by 

 the beacon's blaze, the nocturnal peregrinations of birds follow 

 the same lines as I have just detailed in the case of migrants 

 travelling by day. If, for a moment, we suppose this not to be 

 the case, but rather that the multitudinous assemblies or so- 

 called " rushes " are, by a kind of avian volition, drawn up as 

 the journey is being started, or shortly afterwards, then we 

 should expect visitations of these "rushes" (at all events of 

 the widely distributed and abundant species) more regularly and 

 frequently at our lighthouse lanterns, and not necessarily in only 

 a special phase of the weather. If birds normally migrated in 

 dense throngs at night, their passage in great numbers through 

 the more distant part of the rays of the lantern in clear 

 weather (when they would not be allured to the glass) would at 

 all events be noticeable. But such is not what one sees. 

 Indeed, it is only by watching from the balcony with unremitting 

 attention that one can gather evidence of the analogous features 

 between the migratory flights of birds by night and by day. On 

 a calm night, with a clear and dry atmosphere, so that the rays 



