GENERAL DISTRIBUTION. 
178 
were unknown to suitable species before they settled 
there. As an example of such colonization I may 
mention the common Sparrow, which came first to 
Siberia only after the introduction of cereals ; in like 
manner, it probably emigrated to East Soudan with 
the first introduction of wheat. It cannot, apparently, 
live in any other than an arable country; for in many 
forest-villages it does not exist. In the eastern hemi¬ 
sphere, however, it is found in all places where cereals 
are cultivated, and has become acclimatised in both 
Australia and America. Thus, its geographical distribu¬ 
tion is exceptionably extended, and will probably become 
more so, for this bird has almost merged into a domestic 
animal, and will, probably, follow man over the whole 
earth. 
We know of similar cases of colonization among birds 
in Scotland; the Partridge is supposed to have been 
unknown there previous to the introduction of rye ;* 
the Crested Lark only settled in Westphalia after the 
formation of the high-roads ; and, in Holland, the Purple 
Sandpiper (Tring a maritima ) first appeared as a permanent 
resident with the introduction of stone dykes, f In Murcia, 
in Spain, a few years ago, a single pair of Jackdaws 
made their appearance, birds which, hitherto, were 
unknown in that neighbourhood; they brought up five 
young ones: these again paired, and soon increased to 
* Query oats or barley.— W. J. 
t The Purple Sandpiper does not breed in Hoi]and, and therefore cannot be 
considered as “ bleibend” or a permanent resident: the author here probably 
means, under the term “ Meerstrandlaufer,” the whole family of Tringae and 
Sandpipers; but why they should have deferred residing permanently in Holland 
previous to the introduction of stone dykes is not easily to be understood, unless 
the explanation be that, by reason of repeated floods, the places suitable for 
breeding were rendered untenable. I am indebted to Mr. H. E. Dresser for the 
substance of this note.— W. J. 
