I 
OF SELBOENE, 155 
genera are many of them new, expressive, and masterly. 
He has ventured to alter some of the Linnaean genera with 
sufficient show of reason. 
It might, perhaps, be mere accident that you saw bo 
many swifts, and no swallows, at Staines ; because, in my 
long observation of those birds, I never could discover the 
least degree of rivalry or hostility between the species. 
Ray remarks that birds of the GalUnce order, as cocks 
and hens, partridges and pheasants, &c., are pulveratrices, 
such as dust themselves, using that method of cleansing 
their feathers, and ridding themselves of their vermin. As 
far as I can observe, many birds that dust themselves never 
wash : and I once thought that those birds that wash them- 
selves would never dust ; but here I find myself mistaken ; 
for common house sparrows are great pulveratrices, being 
frequently seen grovelling and wallowing in dusty roads ; 
and yet they are great washers. Does not the skylark 
dust ? 
Query. Might not Mahomet and his followers take ont 
method of purification from these pulveratrices ? because I 
find, from travellers of credit, that if a strict Mussulman is 
journeying in a sandy desert where no water is to be found, 
at stated hours he strips off his clothes, and most scrupulously 
rubs his body over with sand or dust. 
A countryman told me he had found a young fern owl in 
the nest of a small bird on the ground ; and that it was fed 
by the little bird. I went to see this extraordinary phe- 
nomenon, and found that it was a young cuckoo hatched in 
the nest of a titlark : it was become vastly too big for its 
nest, appearing 
in tenui re 
Majores pennas nido extendisse 
and was very fierce and pugnacious, pursuing my fingf^r, as 
I teased it, for many feet from the nest, and sparring and 
bufiFeting with its wings like a game-cock. The dupe of a 
dam appeared at a distance, hovering about with meat in its 
mouth, and expressing the greatest solicitude. 
In July I saw several cuckoos skimmiog over a large 
pond; and found; after some ob*5ervation, that they were 
