THE 1909 IRRUPTION OF THE CROSSBILL. 381 



1910, p. 245; 1911, p. 54), although it is just possible 

 that the appearance of these birds was due to movements 

 northward from England. 



REFERENCES. 



British Birds : Vol. HI., pp. 82-83, 123-125, 162-163, 

 190-194, 226-228 (and maps), 258-261, 302-306, 331- 

 333, 371-375, 400-410; Vol. IV., pp. 20-22, 47-53, 

 81-83, 121-122, 185-187, 211-213, 250. 

 We are also greatly indebted to a number of correspon- 

 dents, who have very kindly given us valuable information 

 concerning the departure of Crossbills from their districts, 

 and this has been incorporated with that derived from 

 published records, under the heading " Departure," 

 above. 



