Who was the first to bite?

There is a sheath around your eyeball.

The Choroid is a lovely thing,
like the "Chorion," its namer.
As wrap around the amnion --
its arteried and stable.
A bounty table so replete,
it's scraps feed all it can:
A mother to her baby girl;
A smile, a suck, a fable.

Less stable are the gripping arms
Of the Ciliary Body -
A crowd of hands on a rubber band
That yank and wrench so rawly!
Pull they do when things go dark
lustful for all they can,
But when the lights go on a-bright...
whistle, relax, no folly.

Too farfetched for you, these guys?
Not surprised am I.
As coated paint, the iris hides
them: colored, free-reside.
A heavy blanket, a lively girl,
Distracts you from their gropes.
But, ah, with color so lovely swirled
The dream is to forget.

All combined -- the mother dear,
the arms, the verdant gal --
Are as to me, it's safe to say,
beloved as my sight.
And yet we name them "uveal,"
Pertaining to the grape.
I'll ask my title to the Latin:
Who was the first to bite?