MIGRA TION 567 



what is called tlie " homing " faculty in Pigeons might furnish a 

 clue, but Mr. Tegetmeier and all the best authorities on that sub- 

 ject declare that a knowledge of landmarks obtained by sight, and 

 sight only, is the sense which directs these Birds, while sight alone 

 can hardly be regarded as affording much aid to Birds — and there 

 is reason to think that there are several such — which at one stretch 

 transport themselves across the breadth of Europe, or even traverse 

 more than a thousand miles of open ocean, to say nothing of those 

 — and of them there are certainly many — which perform their 

 migrations mainly by night. That particular form of Bluethroat 

 which yearly repairs to breed upon the mosses of the Subalpine 

 and Northern parts of Scandinavia {Cyanecula suecica) is hardly ever 

 seen in Europe south of the Baltic' Throughout Germany it may 

 be said to be practically absent, being replaced by a conspicuously 

 different form (C. leucocyana), and as it is a Bird in which the 

 collectors of that country, a numerous and well-instructed body, 

 have long taken great interest, we are in a position to declare that 

 save in Heligoland, it is hardly known to stop in its transit from 

 its winter haunts, which we know to be Egypt and the valley of 

 the Upper Nile, to its breeding-quarters. Other instances, though 

 none so crucial as this, could be cited from among European Birds 

 were there room here for them. In New Zealand there are two 

 Cuckows which are annual visitors : one, a species of Chrysococcyx, 

 probably has its winter quarters in New Guinea, though commonly 

 supposed to come from Australia, the other, Eudynamis taitensis, is 

 widely spread throughout Polynesia, yet both these birds yearly 

 make two voyages over the enormous waste of waters that sur- 

 rounds the country to which they resort to breed. But space 

 would utterly fail us were we to attempt to recount all the ex- 

 amples of these wonderful flights. Yet it seems impossible that 

 the sense of sight should be the faculty whereby they are so guided 

 to their destination, any more than in the case of those which 

 travel in the dark. 



Dr. von Middendorff (Isepipt. Russl. p. 9), from the conclusions 

 he has drawn, as before mentioned, as to the spring-movement of 

 all birds in the Russian Empire being towards the Taimyr Penin- 

 sula, the seat of one of the magnetic poles, has suggested that the 

 migrating Bird is always aware (he does not exactly explain by 



but if that objection be raised tbe circumstance becomes still more puzzling, for 

 then we have to account for some mode of communicating precise information by 

 one bird to another. 



^ It has occurred indeed as a straggler in spring about a dozen times in 

 England, and it arrives twice a year in greater or less numbers in Heligoland as 

 reported by Herr Gatke. Its autumnal visits to this country, occasionally in 

 considerable numbers, seem to be almost annual, though of course they are not 

 always observed. 



