104 
NATUEAL HISTOllY OF SELBOENE. 
crowding towards the coast in order for their departure : but it was 
very extraordinary that I never saw a redstart^ white throaty black-cap, 
uncrested wren, fly-catcher, &c. And I remember to have made the 
same remark in former years, as I usually come to this place annually 
about this time. The birds most common along the coast, at present, 
are the stone-chatters, winchats, buntings, linnets, some few wheat-ears, 
titlarks, &c. Swallows and house-martins abound yet, induced to 
prolong their stay by this soft, still, dry season. 
A land tortoise, which has been kept for thirty years in a little walled 
court belonging to the house where I now am visiting, retires under 
ground about the middle of November, and comes forth again about 
the middle of April. When it first appears in the spring it discovers 
very little inclination towards food; but in the height of summer 
grows voracious ; and then as the summer declines its appetite declines ; 
so that for the last six weeks in autumn it hardly eats at all. Milky 
plants, such as lettuces, dandelions, sowthistles, are its favourite dish. 
In a neighbouring village one was kept till by tradition it was supposed 
to be an hundred years old. An instance of vast longevity in such a 
poor reptile ! 
LETTEE VIIL 
TO THE SAME. 
Selborne, Dec. 20th, 1770. 
Dear Sir, — The birds that I took for aberdavines were reed-sparrows 
{Passeres torquati.) 
There are doubtless many home internal migrations within this 
kingdom that want to be better understood : witness those vast flocks 
of hen chaffinches that appear with us in the winter without hardly 
any cocks among them. Now was there a due proportion of each sex, 
it should seem very improbable that any one district should produce 
such numbers of these little birds ; and much more when only one-half 
of the species appears ; therefore we may conclude that the Fringill(E 
coelebes, for some good purposes, have a peculiar migration of their own 
in which the sexes part. Nor should it seem so wonderful that the 
intercourse of sexes in this species of bird should be interrupted in 
winter ; since in many animals, and particularly in bucks and does, 
the sexes herd separately, except at the season when commerce is 
necessary for the continuance of the breed. For this matter of the 
chaffinches see " Fauna Suecica," p. 58, and " Systema Naturae," p. 318. 
I see every winter vast flights of hen chaffinches, but none of cocks."^ 
Your method of accounting for the periodical motions of the British 
singing birds, or birds of flight, is a very probable one ; since the 
matter of food is a great regulator of the actions and proceedings of 
the brute creation ; there is but one that can be set in competition 
* The words of Linnseus in "Fauna Suecica" (edit. 1746, p. 76), are " Femina 
migrat per hyeraes, mas permanet.^^ In the " Systema Naturae," Femina sola migrat 
'per Belgium in Italiam." — See also, note, Letter XIII. to Pennant, p. 34. 
