Notebooks of Leonardo da Vinci

this text.] 

On corpulency and leanness (809-811). 

809. 

Make the rule and give the measurement of each muscle, and give the
reasons of all their functions, and in which way they work and what
makes them work &c. 

[4] First draw the spine of the back; then clothe it by degrees, one
after the other, with each of its muscles and put in the nerves and
arteries and veins to each muscle by itself; and besides these note
the vertebrae to which they are attached; which of the intestines
come in contact with them; and which bones and other organs &c. 

The most prominent parts of lean people are most prominent in the
muscular, and equally so in fat persons. But concerning the
difference in the forms of the muscles in fat persons as compared
with muscular persons, it shall be described below. 

[Footnote: The two drawings given on Pl. CVIII no. 1 come between
lines 3 and 4. A good and very early copy of this drawing without
the written text exists in the collection of drawings belonging to
Christ's College Oxford, where it is attributed to Leonardo.] 

810. 

Describe which muscles disappear in growing fat, and which become
visible in growing lean. 

And observe that that part which on the surface of a fat person is
most concave, when he grows lean becomes more prominent. 

Where the muscles separate one from another you must give profiles
and where they coalesce ... 

811. 

OF THE HUMAN FIGURE. 

Which is the part in man, which, as he grows fatter, never gains
flesh? 

Or what part which as a man grows lean never falls away with a too
perceptible diminution? And among the parts which grow fat which is
that which grows fattest? 

Among those which grow lean which is that which grows leanest? 

In very strong men which are the muscles which are thickest and most
prominent? 

In your anatomy you must represent all the stages of the limbs from
man's creation to his death, and then till the death of the bone;
and which part of him is first decayed and which is preserved the
longest. 

And in the same way of extreme leanness and extreme fatness. 

The divisions of the head (812. 813). 

812. 

ANATOMY. 

There are eleven elementary tissues:-- Cartilage, bones, nerves,
veins, arteries, fascia, ligament and sinews, skin, muscle and fat. 

OF THE HEAD. 

The divisions of the head are 10, viz. 5 external and 5 internal,
the external are the hair, skin, muscle, fascia and the skull; the
internal are the dura mater, the pia mater, [which enclose] the
brain. The pia mater and the dura mater come again underneath and
enclose the brain; then the rete mirabile, and the occipital bone,
which supports the brain from which the nerves spring. 

813. 

_a_. hair 

_n_. skin 

_c_. muscle 

_m_. fascia 

_o_. skull _i.e._ bone 

_b_. dura mater 

_d_. pia mater 

_f_. brain 

_r_. pia mater, below 

_t_. dura mater