On the Great Invasion of Crossbills in 1909. 331 
is metallic grass-green; the lower back and rump are dull 
azure-blue instead of pale bluish grey; the sides of the head 
and throat dingy bluish green instead of pure white; the 
remainder of the lower parts is bluisln white, more whitish in 
the middle, decidedly tinged with bluish green on the flanks; 
the feathers of the chest are black with the slightly attenu¬ 
ated tips bluish white, but there is no trace of the golden 
yellow tinge, so conspicuous" a feature in C. palmeri ; the 
lesser wing-coverts, bluish grey in the latter, are metallic 
azure blue, more greenish blue at the tips, and shading into 
violet towards the edge of the wing; the edges of the median 
and greater wing-coverts, as well as those of the remiges 
and rectrices, are dull azure blue in C. cabanisi, bluish grey 
in C. palmeri. In the former the base of the lower 
mandible is pale brown, while the latter has the bill entirely 
black. 
The type of C. palmeri (from which the figure (PI. V.) is 
taken) is in the Zoological Museum of Munich. 
XIV.— On the Great Invasion of Crossbills in 1909. 
By Joseph I. S. Whitaker, F.Z.S., M.B.O.U. 
The following notes are the results of an inquiry which I 
have attempted to make regarding the exceptional, and, so 
far as regards recent years, I may say unprecedented, invasion 
of the Common Crossbill (Loxia curvirostra ), which has 
occurred during the past summer and autumn throughout 
a considerable portion of Europe. This inquiry, I may at 
once observe, has no pretension to being a searching or 
exhaustive one. It was, indeed, my original intention to 
write of the Crossbill invasion so far as regards Italy alone, 
but the consideration that it was a matter which concerned 
the whole of Europe has induced me to extend my remarks 
to the wider sphere. 
As in the case of Ballasts Sand-Grouse (Syrrhaptes para¬ 
doxus), partial, although occasionally very considerable, 
migrations of the Crossbill occur, from time to time, at 
