Common Birds. 
107 
price, antl, tTtuliiiL;' his lioI)by ,L;ettin,L;' too costly, gives it up in 
disgusL 'Flic mistake lie makes is in fancying" that he has ex- 
hausted the possibilities of a species by the possession for a few 
years of one or two examples. 
There is not a single species which has yet been adequatel / 
studied. There is any amount of anuisement and instruction 
to be extracted from careful observation of even the commonest 
bird. Let us take for example the Silverbill. ( )f this there are 
two species or varieties, the Indian and the African. Suppose 
the bird-keeper to purchase a dozen of the African (the common 
kind) and a few of the Indian. Let him keep some of them in 
an indoor aviary and some in an outdoor aviary all the year 
round, and some out-of-doors in summer and in-doors in the 
winter. Let him note under which conditions they thrive best. 
Let him experiment by feeding some on canary-seed alone, some 
on white millet seed alone, and some on spray or French millet 
alone, and some on two or more of these seeds. Let him endeav- 
our to find some certain means of distinguishing the sexes. Let 
him observe their nesting habits under differing conditions. Let 
him try the effect of crossing the two kinds, and ascertain 
whether the progeny are fertile.* Let him try whether it be 
])ossible by careful selection to improve the size of the race, or 
perpetuate any interesting " sport '" which may occur among 
his birds. These are a few of the things he may do with a dozen 
or two of Silverbills — one of the very commonest of imported 
foreign finches. Is there not plenty here to occupy the avicul- 
turist for several years? 

Vultures near Calcutta. 
By E. W. H.xrpkr, F.Z.S., M.B.O.U. 
1 am enclosing two snapshots I took a few weeks ago of 
vultures, about five miles outside Calcutta. The place is where 
all dead domestic animals from the city are taken. The bodies 
of horses and cattle are, after being skinned, converted into 
* The Indian and African varieties of the Silverbill have been crossed 
several times, and we have found the young hybrids fertile, both when paired 
among themselves or with the species. — Ed. 
