332 
Mr. Joseph I. S. Whitaker on the 
irregular intervals, varying greatly in their numerical import¬ 
ance, as "well as in their extension and duration. The 
invasion of the past year, however, has been of such magni¬ 
tude and so wide-spread that it cannot fail to have attracted 
the attention of most ornithologists in our own country, as 
well as abroad. 
So far as I am aware, no Report of a comprehensive 
nature, embracing the whole of the European Continent, has 
as yet been published regarding this highly interesting 
ornithological event, although I understand that at least one 
such Report is in course of preparation on the Continent, 
and we may therefore shortly expect to be placed in possession 
of full details and much valuable information on the subject. 
Meanwhile I may say that some interesting local notes and 
letters regarding the course and progress of the invasion have 
appeared from time to time during the past few months, in 
England as well as on the Continent, and some noteworthy 
particulars have been obtained and recorded concerning it. 
Foremost among these particulars, so far as relates to our 
own country, may be mentioned those published in f British 
Birds/ and specially some notes by Mr. H. F. Witherby in 
the November and December parts of that journal, the latter, 
moreover, being accompanied by a series of maps, cleverly 
drawn up by Commander Lynes, illustrating the extent and 
progress of the invasion of Crossbills in the British Islands. 
Letters have also appeared from time to time in the 4 Field 9 
recording the occurrence of this species in various parts of 
the United Kingdom and abroad *. 
In Germany, as well as in Austro-Hungary, and generally, 
I may say, throughout Central Europe, our brother orni¬ 
thologists have not been idle in collecting notes and 
information regarding the unusual appearance of Crossbills 
in their respective countries. 
In France an inquiry into the subject was opened in the 
columns of the ‘ Revue franpaise d'Ornithologie 5 last autumn, 
and some interesting information has been obtained. 
* The details given in the ‘ Annals of Scottish Natural History ’ for 
1909 and 1910 should also he consulted.— Edd. 
