218 Mr. A. Newton on the Irruption of 



commotion or this extraordinary revolution might be. He seems 

 to think that the continuance of a week's violent north-east 

 wind, which preceded the date (June 3rd) when his first ex- 

 ample occurred, may have been sufficient to account for 

 Now that such a wind may have deflected the course of our 

 invaders I am not prepared to deny ; but then we know that ex- 

 amples of this bird had been met with in Europe nearly three 

 weeks before this wind began to blow. I cannot therefore agree 

 to the suggestion*. Another cause has been imagined by Dr. 

 Darracq, who conceives that the birds " pourraient fort bien 

 avoir opere leur migration dans le cours de Fautomue dernier 

 (1862), et leur retour se serait elFectue beaucoup plus tard que 

 chez les autres especes. S'il en etait ainsi, il faudrait admettre 

 qu'ils eussent suivi une route inaccoutumee '' (Rev. Zool. 1863, 

 p. 401). But this, I would submit, does not touch the question. 

 I am more ready to coincide with an expression that follows : 

 — " Toutefois, convenons que Tinstinct d'emigration de la race 

 ailee est tel, qu'il pent dejouer toutes nos theories, mettre a la 

 torture Pesprit scrutateur le mieux exerce et lui causer plus d'une 

 deception." 



In the letter which Mr. Hancock was good enough to place 

 in my hands, and which I have before mentioned. Captain Carr 

 states of these birds, " I think that their appearance in England 

 during the last year or two may be partly accounted for by the 

 colonization of the valley of the Amoor by the Russians, and 

 the probably increased amount of land sown with seed along 

 the roads leading from thence to European Russia. My idea is 

 that some birds, instead of seeking food in the country around 

 Pekin, have gone westward, supplying themselves with food 

 from cultivated lands which a few years ago were in a state of 

 nature — perhaps a desert." But I have said above that we 

 ought not to assume that our visitors came from a region so re- 

 mote as Eastern Siberia ; I therefore must dechne to acknowledge 

 this as the true cause of the irruption. 



Dr. Altum, in the second of his valuable articles on the occur- 

 rence of Syrrhaptes in Borkum, endeavours to account for its 



* I am bound to say, however, that it meets with the approval of no 

 less high an authority than Professor Gratiolet (R. Z. 1863, p. 460). 



