MOTIONS OF INSECTS. 459 
in different orders have them, and some in greater numbers. As I lately 
observed, the foot-cushions of the Buprestes are something very like them, 
minutes were employed to make them so by stretching out her trunk, and passing 
them repeatedly along its sides, apparently for the sake of moistening the flour and 
causing its grains to adhere; for after this operation, on rubbing her tarsi together, 
which she next proceeded to do, I saw distinct little pellets of flour fall down. A 
process almost exactly similar I have always seen used by blue-bottle flies and 
common house-flies, which had their tarsi clogged with flour by walking over it, or 
by having it dusted over them; but these manceuvres are required for an especial 
purpose, and on ordinary occasions, as before observed, the object in rubbing the 
tarsi together is not to clean them, but the pulvilli, for which they serve as brushes, 
Besides rubbing the tarsi together, flies are often seen, while thus employed, to pass 
the two fore tarsi and tibia with sudden jerks over the back of the head and eyes, 
and the two hind tarsi and tibim over and under the wings, and especially over their 
outer margins, and occasionally also over the back of the abdomen. ‘That one object 
of these operations is often to clean these parts from dust I have no doubt, as on 
powdering flies with flour they thus employ themselves, sometimes for ten minutes, 
in detaching every part of it from their eyes, wings, and abdomen; but I am also 
inclined to believe that, in general, when this passing of the legs over the back of 
the head and outer margin of the wings takes place in connection with the ordinary 
rubbing of the tarsi together, as it usually does, that the object is rather for the 
purpose of completing the entire cleansing of the tarsal brushes (for which the row 
of strong hairs visible under a lens on the exterior margin of the wings seems well 
adapted), so that they may act more perfectly on the pulvilli. Here, too, it should 
be noticed, in proof of the importance of all the pulvilli being kept clean, that as 
the tarsi of the two middle legs cannot be applied to each other, flies are constantly 
in the habit of rubbing one of these tarsi and its pulvillus sometimes between the 
two fore tarsi, and at other times between the two hind ones. I ought also not to 
omit stating, that having taken out of a spider’s net one of the minute Chalcidide 
just caught, and pulled away the threads attached to it, it spent some time in 
passing its hinder tarsi over its wings and abdomen, and then in passing its fore 
tarsi through its palpi, apparently, as in the case of flies, to clean its pulvilli from 
any remains of the spider’s net; and that having surrounded a minute beetle (Meli- 
gethes @neus), which chanced to be on the window, with a slight circle of moisture, 
it was unable to pass through it, and repeatedly drew its wetted fore tarsi through 
its mouth, and rubbed the hind tarsi together; and that precisely the same sostits 
took place in the case of an Zchneumon placed in similar circumstances, only it spent 
much more time in rubbing both its fore and hind tarsi together after being wetted, 
and in passing the former over its antenne and through its mouth; and when 
powdered with flour, it spent, like the flies before mentioned, some minutes in 
cleaning itself by the same processes. 
Though the above observations, hastily made on the spur of the occasion since 
beginning this note, seem to prove that it is necessary the pulvilli of flies and of 
some other insects: should be kept free from moisture and dust to enable them to 
ascend vertical polished surfaces, they cannot be considered as wholly settling the 
question as to the precise way in which these pulvilli, and those of insects generally, 
act in effecting a similar mode of progression; and my main reason for here giving 
these slight hints is the hope of directing the attention of entomological and micro= 
Scopical observers to a field evidently, as yet, so imperfectly explored. 
After writing the above, intended as the conclusion of this long note, I witnessed 
to-day (July 11, 1842), a fact which I cannot forbear adding to it. Observing a 
house-fly on the window, whose motions seemed very strange, I approached it, and 
found that it was making violent contortions, as though every leg were affected 
with St. Vitus’s dance, in order to pull its pulvilli from the surface of the glass, to 
which they adhered so strongly that though it could drag them a little way, or 
Sometimes by a violent effort get first one and then another detached, yet the 
moment they were placed on the glass again, they adhered as if their under side 
were smeared with bird-lime, Once it succeeded in dragging off its two fore legs, 
