Producing the Blue Budgerigar. 217 
jurious to certain i)arts of the body, especially to the leucocytis, 
or white blood corii)uscIes. Nature provides a colour screen, 
especially in tropical countries, to filter out the actinic rays 
in the shape of black, red or yellow colouring-. So when the 
yellow is removed from a bird's protective colourin'g,, the 
bird itself should be removed from the danger against which 
it needs protection. 
Also I think that so long as birds are allowed to go 
into the strong sunlight, there will be an imperative call on 
the part of Nature for the natural form of protection, which 
in consequence will result in the production of protective 
colouring. If the need for protective colouring be removed, 
by breeding Budgerigars in the shade, it will conduce to the 
non-production of the yellow. 
I am afraid this sounds very theoretical and not .the 
least interesting, but I venture to think it is worth a trial. 
In conclusion, I ladd that I have found those Budgerigars with 
most blue .and least yellow in their colouring are, as a rule, 
both small and delicate. 
Bird Marking. 
By Dr. Philip Gosse, M.B.O.U. 
The following is a short account of the birds marked with, 
migration rings this season : March to the en d of July this year. 
Nearly all the birds given in the list below, were marked 
as young birds in the immediate neighbourhood of the village of 
Beaulieu, in South Hampshire. The rings used are those of the 
Aberdeen University Migration Inquiry. They are made of 
aluminium, in several sizes, and each ring is stamped with a 
consecutive number and the address " Aberdeen Univ." 
The object of the scheme is to help to unravel the mystery 
of the migi-ation of birds. The actual returns are very few, but 
every one that is found and reported, supplies one definite fact, so 
that in time, it is to be hoped our knowledge of the movements of 
birds will be greatly increased- It may seem surprising that the 
bird to head the list should be the Blue Tit, of which 162 were 
marked. The explanation of this is that we have about 40 nesting 
boxes, of various sizes, in two woods, and most of those with the 
small openings are inhabited by Blue Tits. Although this is only 
the second year that these boxes have been up, there is already a 
