Notebooks of Leonardo da Vinci

This is found in the province of Cyrenaica and is not more than 12
fingers long. It has on its head a white spot after the fashion of a
diadem. It scares all serpents with its whistling. It resembles a
snake, but does not move by wriggling but from the centre forwards
to the right. It is said that one 

1256. 

of these, being killed with a spear by one who was on horse-back,
and its venom flowing on the spear, not only the man but the horse
also died. It spoils the wheat and not only that which it touches,
but where it breathes the grass dries and the stones are split. 

THE WEASEL. 

This beast finding the lair of the basilisk kills it with the smell
of its urine, and this smell, indeed, often kills the weasel itself.

THE CERASTES. 

This has four movable little horns; so, when it wants to feed, it
hides under leaves all of its body except these little horns which,
as they move, seem to the birds to be some small worms at play. Then
they immediately swoop down to pick them and the Cerastes suddenly
twines round them and encircles and devours them. 

1257. 

THE AMPHISBOENA. 

This has two heads, one in its proper place the other at the tail;
as if one place were not enough from which to fling its venom. 

THE IACULUS. 

This lies on trees, and flings itself down like a dart, and pierces
through the wild beast and kills them. 

THE ASP. 

The bite of this animal cannot be cured unless by immediately
cutting out the bitten part. This pestilential animal has such a
love for its mate that they always go in company. And if, by mishap,
one of them is killed the other, with incredible swiftness, follows
him who has killed it; and it is so determined and eager for
vengeance that it overcomes every difficulty, and passing by every
troop it seeks to hurt none but its enemy. And it will travel any
distance, and it is impossible to avoid it unless by crossing water
and by very swift flight. It has its eyes turned inwards, and large
ears and it hears better than it sees. 

1258. 

THE ICHNEUMON. 

This animal is the mortal enemy of the asp. It is a native of Egypt
and when it sees an asp near its place, it runs at once to the bed
or mud of the Nile and with this makes itself muddy all over, then
it dries itself in the sun, smears itself again with mud, and thus,
drying one after the other, it makes itself three or four coatings
like a coat of mail. Then it attacks the asp, and fights well with
him, so that, taking its time it catches him in the throat and
destroys him. 

THE CROCODILE. 

This is found in the Nile, it has four feet and lives on land and in
water. No other terrestrial creature but this is found to have no
tongue, and it only bites by moving its upper jaw. It grows to a
length of forty feet and has claws and is armed with a hide that
will take any blow. By day it is on land and at night in the water.
It feeds on fishes, and going to sleep on the bank of the Nile with
its mouth open, a bird called 

1259. 

trochilus, a very small bird, runs at once to its mouth and hops
among its teeth and goes pecking out the remains of the food, and so
inciting it with voluptuous delight tempts it to open the whole of
its mouth, and so it sleeps. This being observed by the ichneumon it
flings itself into its mouth and perforates its stomach and bowels,
and finally kills it. 

THE DOLPHIN. 

Nature has given such knowledge to animals, that besides the
consciousness of their own advantages they know the disadvantages of
their foes. Thus the dolphin understands what strength lies in a cut
from the fins placed on his chine, and how tender is the belly of
the crocodile; hence in fighting with him it thrusts at him from
beneath and rips up his belly and so kills him. 

The crocodile is a terror to those that flee, and a base coward to
those that pursue him. 

1260. 

THE HIPPOPOTAMUS.