Why did nature not ordain that one animal should not live by the
death of another? Nature, being inconstant and taking pleasure in
creating and making constantly new lives and forms, because she
knows that her terrestrial materials become thereby augmented, is
more ready and more swift in her creating, than time in his
destruction; and so she has ordained that many animals shall be food
for others. Nay, this not satisfying her desire, to the same end she
frequently sends forth certain poisonous and pestilential vapours
upon the vast increase and congregation of animals; and most of all
upon men, who increase vastly because other animals do not feed upon
them; and, the causes being removed, the effects would not follow.
This earth therefore seeks to lose its life, desiring only continual
reproduction; and as, by the argument you bring forward and
demonstrate, like effects always follow like causes, animals are the
image of the world.

_XX._

_Humorous Writings._

_Just as Michaelangelo's occasional poems reflect his private life
as well as the general disposition of his mind, we may find in the
writings collected in this section, the transcript of Leonardo's
fanciful nature, and we should probably not be far wrong in
assuming, that he himself had recited these fables in the company of
his friends or at the court festivals of princes and patrons._ Era
tanto piacevole nella conversazione-- _so relates Vasari_--che
tirava a se gli animi delle genti. _And Paulus Jovius says in his
short biography of the artist:_ Fuit ingenio valde comi, nitido,
liberali, vultu autem longe venustissimo, et cum elegantiae omnis
deliciarumque maxime theatralium mirificus inventor ac arbiter
esset, ad lyramque scito caneret, cunctis per omnem aetatem
principibus mire placuit. _There can be no doubt that the fables are
the original offspring of Leonardo's brain, and not borrowed from
any foreign source; indeed the schemes and plans for the composition
of fables collected in division V seem to afford an external proof
of this, if the fables themselves did not render it self-evident.
Several of them-- for instance No._ l279--_are so strikingly
characteristic of Leonardo's views of natural science that we cannot
do them justice till we are acquainted with his theories on such
subjects; and this is equally true of the 'Prophecies'_.

_I have prefixed to these quaint writings the 'Studies on the life
and habits of animals' which are singular from their peculiar
aphoristic style, and I have transcribed them in exactly the order
in which they are written in MS. H. This is one of the very rare
instances in which one subject is treated in a consecutive series of
notes, all in one MS., and Leonardo has also departed from his
ordinary habits, by occasionally not completing the text on the page
it is begun. These brief notes of a somewhat mysterious bearing have
been placed here, simply because they may possibly have been
intended to serve as hints for fables or allegories. They can
scarcely be regarded as preparatory for a natural history, rather
they would seem to be extracts. On the one hand the names of some of
the animals seem to prove that Leonardo could not here be recording
observations of his own; on the other hand the notes on their habits
and life appear to me to dwell precisely on what must have
interested him most--so far as it is possible to form any complete
estimate of his nature and tastes._

_In No._ 1293 _lines_ 1-10, _we have a sketch of a scheme for
grouping the Prophecies. I have not however availed myself of it as
a clue to their arrangement here because, in the first place, the
texts are not so numerous as to render the suggested classification
useful to the reader, and, also, because in reading the long series,
as they occur in the original, we may follow the author's mind; and
here and there it is not difficult to see how one theme suggested
another. I have however regarded Leonardo's scheme for the
classification of the Prophecies as available for that of the Fables
and Jests, and have adhered to it as far as possible._

_Among the humourous writings I might perhaps have included the_
'Rebusses', _of which there are several in the collection of
Leonardo's drawings at Windsor; it seems to me not likely that many
or all of them could be solved at the present day and the MSS. throw
no light on them. Nor should I be justified if I intended to include
in the literary works the well-known caricatures of human faces
attributed to Leonardo-- of which, however, it may be incidentally
observed, the greater number are in my opinion undoubtedly spurious.
Two only have necessarily been given owing to their presence in
text, which it was desired to reproduce: Vol. I page_ 326, _and Pl.
CXXII. It can scarcely be doubted that some satirical intention is
conveyed by the drawing on Pl. LXIV (text No. _688_).

My reason for not presenting Leonardo to the reader as a poet is the
fact that the maxims and morals in verse which have been ascribed to
him, are not to be found in the manuscripts, and Prof. Uzielli has
already proved that they cannot be by him. Hence it would seem that
only a few short verses can be attributed to him with any
certainty._

I.

STUDIES ON THE LIFE AND HABITS OF ANIMALS.