INTRODUCTION. 
97 
number of plain coloured species, 'which would 
certainly not have been transmitted with the more 
attractive sorts, had not variety been consulted by 
the dealers, in what they call their “ assortment,” as 
much as beauty. In the second place, this splendour 
of plumage is in unison with that law which renders 
the productions of nature more rich and luxuriant, 
whether in growth or colours, in proportion as the 
countries they inhabit approximate the equinoctial 
line. This we find in the splendid variety of birds 
on the opposite coast of America, and in those far 
more magnificent races which inhabit the torrid 
islands of the Indian Ocean. The forests of Parra 
contain the most splendid of all the Brazilian birds, 
while it will bo remembered that the whole of the 
paradise birds are restricted to New Guinea and the 
little isles of Aro and Banda in the Malayan seas. 
It may be reasonably inferred, also, both from 
this richness of colour, and from the particular fa- 
milies to which many of these birds belong, that 
they have been met with in a woody country where 
the vegetation is also luxuriant, and where insects 
and fruits, — the two chief sources of nourishment 
to birds, — are in plenty and perfection. We have 
indeed no positive information on the geographic 
features of the districts, or of the precise localities 
where these birds were collected; but by far the 
largest proportion of them feed upon insects which 
inhabit the vicinity of woods, or upon fruits which 
grow therein. The collection contains very few of 
those genera which live only in open plains or in 
G 
