342 
OBSERVATIONS OlSi 
Ivy is the last flower that supports the hymenopteroua 
and dipterous insects. On sunny days^ quite on to Novem- 
ber, they swarm on trees covered with this plant ; and when 
they disappear, probably retire under the shelter of its 
leaves, concealing themselves between its fibres and the 
trees which it entwines/ 
Spiders, woodlice, Lepismce in cupboards and among 
sugar, some Empides, gnats, flies of several species, some 
Phalcence in hedges, earthworms, &c., are stirring at all 
times, when winters are mild ; and are of great service to 
those soft-billed birds that never leave us. 
On every sunny day the winter through, clouds of insects, 
usually called gnats (I suppose Tipulce and Empides) appear 
sporting and dancing over the tops of the evergreen trees 
in the shrubbery, and frisking about as if the business of 
generation was still going on. Hence it appears that these 
Diptera (which by their sizes appear to be of diff'erent species) 
are not subject to a torpid state in the winter as most 
winged insects are. At night, and in frosty weather, and 
when it rains and blows, they seem to retire into those trees. 
They often are out in a fog.'^ 
HUMMING IN THE AIR. 
There is a natural occurrence to be met with upon the 
highest part of our down in hot summer days, which always 
amuses me much, without giving me any satisfaction with 
respect to the cause of it ; and that is a loud audible hum- 
ming of bees in the air, though not one insect is to be seen. 
This sound is to be heard distinctly the whole common 
through, from the Money-dells, to Mr. White's avenue gate. 
Any person would suppose that a large swarm of bees was 
nesting now in many counties where formerly it was chiefly observed a? 
a winter visitant. Cf. " Handbook of British Birds," p. 29. — Ed. 
^ This I have often observed, having seen bees and other winged 
insects swarming about the flowers of the ivy very late in the autumn. 
— Markwick. 
2 This I have also seen, and have frequently observed swarms of 
little winged insects playing up and down in the air in the middle of 
winter, even when the ground has been covered with snow. — ^Markwick. 
