118 
NATURAL HISTORY 
also as they play and toy about on the wing; and particu- 
larly while they are descending, and sometimes as they 
stand on the ground. 
Adanson's testimony seems to me to be a very poor 
evidence that European swallows migrate during our winter 
to SenegaL He does not talk at all like an ornithologist, 
and probably saw only the swallows of that country, which 
I know build within Governor 0^ Harass hall against the 
roof. Had he known European swallows, would he not 
have mentioned the species ? 
The house swallow washes by dropping into the water as 
it flies. This species appears commonly about a week 
before the house martin, and about ten or twelve days before 
the swift. 
In 1772 there were young house martins in their nest 
till October the 23rd. 
The swift appears about ten or twelve days later than 
the house swallow, viz., about the 24th or 26th of April. 
. Whinchats and stonechats stay with us the whole year.^ 
Some wheatears continue with us the winter through. 
Wagtails, all sorts," remain with us all the winter. 
Bullfinches, when fed on hempseed, often become wholly 
black.' 
We have vast flocks of female chafiinches * all the winter, 
with hardly any males among them. 
^ We know of no instance in which the wLincbat has been found 
here in winter, although the stonechat occasionally passes that season 
with us. It is possible that female stonechats may have been mis- 
taken for whinchats, and may thus have given occasion to the above 
remark. — Ed. 
^ The pied wagtail, MotaciUa Yarrellii^ and the grey wagtail, 
M. boarula. As to the latter, which White elsewhere calls the yeUow 
wagtail, see p. 47, note 4. — Ed. 
^ Bullfinches are not the only birds which have been observed to turn 
black from feeding on hempseed, nor is hempseed the only seed which 
conduces to such a change of colour. Larks have been known to 
become black after being fed for some time on hempseed ; and the late 
Mr. Blyth informed us that he had seen one of the little Amandavat 
finches which had become black, though fed entirely on canary 
seed. — Ed. 
* " British Zoology," vol. ii. p. 306. See also Letter XIII. to Pennant, 
p. 46.— Ed. 
