224 THE NATURAL HISTORY OF SELBORNE. 
Linnzus ranks this species of fish under the genus of Cyprinus, 
or carp, and calls it Cyprinus auratus. 
Some people exhibit this sort of fish in a very fanciful way ; 
for they cause a glass bowl to be blown with a large hollow 
space within, that does not communicate with it. In this 
cavity they put a bird occasionally; so that you may see a 
goldfinch or a linnet hopping as it were in the midst of the 
water, and the fishes swimming in a circle round it. The 
simple exhibition of the fishes is agreeable and pleasant; but 
in so complicated a way becomes whimsical and unnatural, 
and liable to the objection due to him, “ who strangely likes to 
vary every single thing.” 
LETTER L. 
October roth, 1781. 
I think I have observed before that much of the most — 
considerable part of the house-martins withdraw from hence 
about the first week in October; but that some, the latter 
broods I am now convinced, linger on till towards the middle 
of that month; and that at times, once perhaps in two or 
three years, a flight, for one day only, has shown itself in the 
first week in November. 
Having taken notice, in October, 1780, that the last flight 
was numerous, amounting perhaps to one hundred and fifty; 
and that the season was soft and still; I was resolved to pay 
uncommon attention to these late birds, to find, if possible, 
where they roosted, and to determine the precise time of their 
retreat. The mode of life of these latter Arundines is very 
favorable to such a design ; for they spend the whole day in 
the sheltered district, between me and the Hanger, sailing 
about in a placid, easy manner, and feasting on those insects 
which love to haunt a spot so secure from ruffling winds. As 
