292 NATURAL HISTORY 
went at once into a nest, where it stayed a short 
time, and then flew over the houses ; fur some days 
after no martins were observed, nor till the 16th of 
April, and then only a pair. Martins in general 
were remarkably late this year. 
LETTER XLVIII. 
Selborne, Sept. 9, 1781. 
I HAVE just met with a circumstance respecting 
swifts which furnishes an exception to the whole 
tenour of my observations ever since | have be- 
stowed any attention on that species of hzrundines. 
Our swifts in general withdrew this year about the 
1st day of August, all save one pair, which in two 
or three days was reduced to a single bird. The 
perseverance of this individual made me suspect 
that the strongest motives, that of an attachment 
to her young, could alone occasion so late a stay. 
I watched, therefore, till the 24th of August, and 
then discovered that under the eaves of the church 
she attended upon two young, which were fledged, 
and now put out their white chins from a crevice. 
These remained till the 27th, looking more alert 
every day, and seeming to long to be on the wing. 
After this day they were missing at once; nor 
could I ever observe them with their dam coursing 
round the church in the act of learning to fly, as 
the first broods evidently do. On the 31st I caused 
the eaves to be searched, but we found in the nest 
only two callow, dead swifts, on which a second 
nest had been formed. This double nest was full 
