HABITS AND COLORATION OF THE STARLING. 285 
‘*No practical result came from all this trouble and expendi- 
ture. . . . The conclusion arrived at was that, while Starlings 
from Western England were apparently true Sturnus vulgaris, 
indistinguishable from the typical Swedish bird, a number of 
those from the east and south of England were intermediate 
between the true S. vulgaris and S. menzbiert, being much more 
purple than green on the head. The inference was that the 
Siberian Starling, extending its range westward, interbred with 
the ordinary S. vulgaris of Western Europe, and that the result 
was a mixture, just as in the case of the Carrion Crow and the 
Hooded Crow.” 
No observer can deny that the Starling in England to-day is, 
for good or for bad, directly or indirectly, a tremendous factor 
in agriculture and forestry. Its yearly increase in most districts 
(if not in all) is obvious to everybody. We can hardly collect 
too much information relating to its range, habits, or past 
history, and we cannot too greatly deplore the way in which 
most students have neglected these questions. Perhaps the 
country is now too well colonized for us to discover the sources 
and the paths of the invaders, or even to be certain that the 
present hordes are descended or not from the indigenous stock. 
Something may be derived from a study of the psychology of 
the bird, as I have indicated in the first part of this paper, but I 
shall endeavour to prove that we can get but equivocal results 
from the consideration of colour, or of races or subspecies that 
are based on colour. 
The plumage of the Starling offers a good example of what 
have been not very happily called ‘‘ metallic colours,” but the 
term is a well-known one, and it is not necessary here to present 
a substitute. A Kingfisher’s feathers, although they change in 
accordance with the positions of the observer and the light, are 
not metallic in the ordinary acceptance of the word (cf. Zool. 
1910, pp. 462-470), but the feathers of the Peacock, Humming- 
Bird, the speculum of a Duck’s wing, &c., are metallic. Several 
attempts have been made to solve the problem of the cause of 
these changing effects, and two distinct explanations have been 
given, but only one has been generally accepted by British 
ornithologists. Unfortunately, this one suffers from two defects: 
it is based upon the presence of structures that have never been 
