he world. After I had studied over
the latter for a time, I remarked that every species almost that came
from distant regions, such as South America, the coast of Guinea, etc.,
were thick-billed birds of the _loxia_ and _fringilla_ genera; and no
_motacillae_, or _muscicapae_, were to be met with. When I came to
consider, the reason was obvious enough, for the hard-billed birds
subsist on seeds which are easily carried on board, while the soft-billed
birds, which are supported by worms and insects, or, what is a
_succedaneum_ for them, fresh raw meat, can meet with neither in long and
tedious voyages. It is from this defect of food that our collections
(curious as they are) are defective, and we are deprived of some of the
most delicate and lively genera.

I am, etc.

LETTER XXXI.

SELBORNE, _Sept. 14th_, 1770.

Dear Sir,--You saw, I find, the ring-ousels again among their native
crags, and are farther assured that they continue resident in those cold
regions the whole year. From whence then do our ring-ousels migrate so
regularly every September, and make their appearance again, as if in
their return, every April? They are more early this year than common,
for some were seen at the usual hill on the fourth of this month.

An observing Devonshire gentleman tells me that they frequent some parts
of Dartmoor, and breed there, but leave those haunts about the end of
September, or beginning of October, and return again about the end of
March.

Another intelligent person assures me that they breed in great abundance
all over the peak of Derby, and are called there tor-ousels, withdraw in
October and November, and return in spring. This information seems to
throw some light on my new migration.

Scopoli's new work (which I have just procured) has its merit in
ascertaining many of the birds of the Tirol and Carniola. Monographers,
come from whence they may, have, I think, fair pretence to challenge some
regard and approbation from the lovers of natural history; for, as no man
can alone investigate the works of nature, these partial writers may,
each in their department, be more accurate in their discoveries, and
freer from errors, than more general writers; and so by degrees may pave
the way to an universal correct natural history. Not that Scopoli is so
circumstantial and attentive to the life and